diff --git a/CHANGES.rst b/CHANGES.rst
index 66a72174..a86e5811 100644
--- a/CHANGES.rst
+++ b/CHANGES.rst
@@ -3,6 +3,11 @@ All notable changes to this project will be documented in this file.
 The format is based on `Keep a Changelog <https://keepachangelog.com/en/1.0.0/>`_,
 and this project adheres to `Semantic Versioning <https://semver.org/spec/v2.0.0.html>`_.
 
+Added
+*****
+
+- OIDC `prompt=create` support. :issue:`185` :pr:`164`
+
 Fixed
 *****
 
@@ -13,6 +18,7 @@ Fixed
 
 Added
 *****
+
 - ``THEME`` can be a relative path
 
 [0.0.39] - 2023-12-15
diff --git a/canaille/oidc/endpoints.py b/canaille/oidc/endpoints.py
index 2796cac8..e09dc1a1 100644
--- a/canaille/oidc/endpoints.py
+++ b/canaille/oidc/endpoints.py
@@ -34,6 +34,7 @@
 from .oauth import require_oauth
 from .oauth import RevocationEndpoint
 from .utils import SCOPE_DETAILS
+from .well_known import openid_configuration
 
 
 bp = Blueprint("endpoints", __name__, url_prefix="/oauth")
@@ -54,6 +55,23 @@ def authorize():
     if not client:
         abort(400, "Invalid client.")
 
+    # https://openid.net/specs/openid-connect-prompt-create-1_0.html#name-authorization-request
+    # If the OpenID Provider receives a prompt value that it does
+    # not support (not declared in the prompt_values_supported
+    # metadata field) the OP SHOULD respond with an HTTP 400 (Bad
+    # Request) status code and an error value of invalid_request.
+    # It is RECOMMENDED that the OP return an error_description
+    # value identifying the invalid parameter value.
+    if (
+        request.args.get("prompt")
+        and request.args["prompt"]
+        not in openid_configuration()["prompt_values_supported"]
+    ):
+        return {
+            "error": "invalid_request",
+            "error_description": f"prompt '{request.args['prompt'] }' value is not supported",
+        }, 400
+
     user = current_user()
     requested_scopes = request.args.get("scope", "").split(" ")
     allowed_scopes = client.get_allowed_scope(requested_scopes).split(" ")
@@ -65,6 +83,10 @@ def authorize():
             return jsonify({"error": "login_required"})
 
         session["redirect-after-login"] = request.url
+
+        if request.args.get("prompt") == "create":
+            return redirect(url_for("core.account.join"))
+
         return redirect(url_for("core.auth.login"))
 
     if not user.can_use_oidc:
diff --git a/canaille/oidc/well_known.py b/canaille/oidc/well_known.py
index 72704341..df03fd23 100644
--- a/canaille/oidc/well_known.py
+++ b/canaille/oidc/well_known.py
@@ -1,4 +1,5 @@
 from flask import Blueprint
+from flask import current_app
 from flask import g
 from flask import jsonify
 from flask import request
@@ -76,7 +77,8 @@ def openid_configuration():
         ],
         "subject_types_supported": ["pairwise", "public"],
         "id_token_signing_alg_values_supported": ["RS256", "ES256", "HS256"],
-        "prompt_values_supported": ["none"],
+        "prompt_values_supported": ["none"]
+        + (["create"] if current_app.config.get("ENABLE_REGISTRATION") else []),
     }
 
 
diff --git a/doc/specifications.rst b/doc/specifications.rst
index 8b5c6851..c61e5a61 100644
--- a/doc/specifications.rst
+++ b/doc/specifications.rst
@@ -40,7 +40,7 @@ OpenID Connect
 - ❌ `OpenID Connect Back Channel Logout <https://openid.net/specs/openid-connect-backchannel-1_0.html>`_
 - ❌ `OpenID Connect Back Channel Authentication Flow <https://openid.net/specs/openid-client-initiated-backchannel-authentication-core-1_0.html>`_
 - ❌ `OpenID Connect Core Error Code unmet_authentication_requirements <https://openid.net/specs/openid-connect-unmet-authentication-requirements-1_0.html>`_
-- ❌ `Initiating User Registration via OpenID Connect 1.0 <https://openid.net/specs/openid-connect-prompt-create-1_0.html>`_
+- ✅ `Initiating User Registration via OpenID Connect 1.0 <https://openid.net/specs/openid-connect-prompt-create-1_0.html>`_
 
 Comparison with other providers
 ===============================
diff --git a/tests/core/test_registration.py b/tests/core/test_registration.py
index c7f39305..bd5080d3 100644
--- a/tests/core/test_registration.py
+++ b/tests/core/test_registration.py
@@ -71,6 +71,10 @@ def test_registration_with_email_validation(testclient, backend, smtpd):
         res.form["family_name"] = "newuser"
         res = res.form.submit()
 
+    assert res.flashes == [
+        ("success", "Your account has been created successfully."),
+    ]
+
     user = models.User.get()
     assert user
     user.delete()
diff --git a/tests/oidc/conftest.py b/tests/oidc/conftest.py
index ed5d3fc8..969a4fbb 100644
--- a/tests/oidc/conftest.py
+++ b/tests/oidc/conftest.py
@@ -41,7 +41,7 @@ def configuration(configuration, keypair):
 
 
 @pytest.fixture
-def client(testclient, other_client, backend):
+def client(testclient, trusted_client, backend):
     c = models.Client(
         client_id=gen_salt(24),
         client_name="Some client",
@@ -69,7 +69,7 @@ def client(testclient, other_client, backend):
         token_endpoint_auth_method="client_secret_basic",
         post_logout_redirect_uris=["https://mydomain.tld/disconnected"],
     )
-    c.audience = [c, other_client]
+    c.audience = [c, trusted_client]
     c.save()
 
     yield c
@@ -77,7 +77,7 @@ def client(testclient, other_client, backend):
 
 
 @pytest.fixture
-def other_client(testclient, backend):
+def trusted_client(testclient, backend):
     c = models.Client(
         client_id=gen_salt(24),
         client_name="Some other client",
@@ -104,6 +104,7 @@ def other_client(testclient, backend):
         jwks_uri="https://myotherdomain.tld/jwk",
         token_endpoint_auth_method="client_secret_basic",
         post_logout_redirect_uris=["https://myotherdomain.tld/disconnected"],
+        preconsent=True,
     )
     c.audience = [c]
     c.save()
diff --git a/tests/oidc/test_authorization_code_flow.py b/tests/oidc/test_authorization_code_flow.py
index 8af21eb5..dc2a5cd3 100644
--- a/tests/oidc/test_authorization_code_flow.py
+++ b/tests/oidc/test_authorization_code_flow.py
@@ -13,7 +13,7 @@
 
 
 def test_authorization_code_flow(
-    testclient, logged_user, client, keypair, other_client
+    testclient, logged_user, client, keypair, trusted_client
 ):
     assert not models.Consent.query()
 
@@ -81,13 +81,13 @@ def test_authorization_code_flow(
     claims = jwt.decode(access_token, keypair[1])
     assert claims["sub"] == logged_user.user_name
     assert claims["name"] == logged_user.formatted_name
-    assert claims["aud"] == [client.client_id, other_client.client_id]
+    assert claims["aud"] == [client.client_id, trusted_client.client_id]
 
     id_token = res.json["id_token"]
     claims = jwt.decode(id_token, keypair[1])
     assert claims["sub"] == logged_user.user_name
     assert claims["name"] == logged_user.formatted_name
-    assert claims["aud"] == [client.client_id, other_client.client_id]
+    assert claims["aud"] == [client.client_id, trusted_client.client_id]
 
     res = testclient.get(
         "/oauth/userinfo",
@@ -114,7 +114,7 @@ def test_invalid_client(testclient, logged_user, keypair):
 
 
 def test_authorization_code_flow_with_redirect_uri(
-    testclient, logged_user, client, keypair, other_client
+    testclient, logged_user, client, keypair, trusted_client
 ):
     assert not models.Consent.query()
 
@@ -161,7 +161,7 @@ def test_authorization_code_flow_with_redirect_uri(
 
 
 def test_authorization_code_flow_preconsented(
-    testclient, logged_user, client, keypair, other_client
+    testclient, logged_user, client, keypair, trusted_client
 ):
     assert not models.Consent.query()
 
@@ -209,7 +209,7 @@ def test_authorization_code_flow_preconsented(
     claims = jwt.decode(id_token, keypair[1])
     assert logged_user.user_name == claims["sub"]
     assert logged_user.formatted_name == claims["name"]
-    assert [client.client_id, other_client.client_id] == claims["aud"]
+    assert [client.client_id, trusted_client.client_id] == claims["aud"]
 
     res = testclient.get(
         "/oauth/userinfo",
@@ -584,7 +584,7 @@ def test_authorization_code_flow_when_consent_already_given_but_for_a_smaller_sc
 
 
 def test_authorization_code_flow_but_user_cannot_use_oidc(
-    testclient, user, client, keypair, other_client
+    testclient, user, client, keypair, trusted_client
 ):
     testclient.app.config["ACL"]["DEFAULT"]["PERMISSIONS"] = []
     user.reload()
@@ -645,16 +645,17 @@ def test_nonce_not_required_in_oauth_requests(testclient, logged_user, client):
 
 
 def test_authorization_code_request_scope_too_large(
-    testclient, logged_user, keypair, other_client
+    testclient, logged_user, keypair, client
 ):
     assert not models.Consent.query()
-    assert "email" not in other_client.scope
+    client.scope = ["openid", "profile", "groups"]
+    client.save()
 
     res = testclient.get(
         "/oauth/authorize",
         params=dict(
             response_type="code",
-            client_id=other_client.client_id,
+            client_id=client.client_id,
             scope="openid profile email",
             nonce="somenonce",
         ),
@@ -671,7 +672,7 @@ def test_authorization_code_request_scope_too_large(
         "profile",
     }
 
-    consents = models.Consent.query(client=other_client, subject=logged_user)
+    consents = models.Consent.query(client=client, subject=logged_user)
     assert set(consents[0].scope) == {
         "openid",
         "profile",
@@ -683,15 +684,15 @@ def test_authorization_code_request_scope_too_large(
             grant_type="authorization_code",
             code=code,
             scope="openid profile email groups address phone",
-            redirect_uri=other_client.redirect_uris[0],
+            redirect_uri=client.redirect_uris[0],
         ),
-        headers={"Authorization": f"Basic {client_credentials(other_client)}"},
+        headers={"Authorization": f"Basic {client_credentials(client)}"},
         status=200,
     )
 
     access_token = res.json["access_token"]
     token = models.Token.get(access_token=access_token)
-    assert token.client == other_client
+    assert token.client == client
     assert token.subject == logged_user
     assert set(token.scope) == {
         "openid",
diff --git a/tests/oidc/test_authorization_prompt.py b/tests/oidc/test_authorization_prompt.py
index ac337843..b0f53652 100644
--- a/tests/oidc/test_authorization_prompt.py
+++ b/tests/oidc/test_authorization_prompt.py
@@ -2,11 +2,14 @@
 Tests the behavior of Canaille depending on the OIDC 'prompt' parameter.
 https://openid.net/specs/openid-connect-core-1_0.html#AuthorizationEndpoint
 """
+import datetime
 import uuid
 from urllib.parse import parse_qs
 from urllib.parse import urlsplit
 
 from canaille.app import models
+from canaille.core.account import RegistrationPayload
+from flask import url_for
 
 
 def test_prompt_none(testclient, logged_user, client):
@@ -98,3 +101,125 @@ def test_prompt_no_consent(testclient, logged_user, client):
         status=200,
     )
     assert "consent_required" == res.json.get("error")
+
+
+def test_prompt_create_logged(testclient, logged_user, client):
+    """
+    If prompt=create and user is already logged in,
+    then go straight to the consent page.
+    """
+    testclient.app.config["ENABLE_REGISTRATION"] = True
+
+    consent = models.Consent(
+        consent_id=str(uuid.uuid4()),
+        client=client,
+        subject=logged_user,
+        scope=["openid", "profile"],
+    )
+    consent.save()
+
+    res = testclient.get(
+        "/oauth/authorize",
+        params=dict(
+            response_type="code",
+            client_id=client.client_id,
+            scope="openid profile",
+            nonce="somenonce",
+            prompt="create",
+        ),
+        status=302,
+    )
+    assert res.location.startswith(client.redirect_uris[0])
+
+    consent.delete()
+
+
+def test_prompt_create_registration_disabled(testclient, trusted_client, smtpd):
+    """
+    If prompt=create but Canaille registration is disabled,
+    an error response should be returned.
+
+         If the OpenID Provider receives a prompt value that it does
+         not support (not declared in the prompt_values_supported
+         metadata field) the OP SHOULD respond with an HTTP 400 (Bad
+         Request) status code and an error value of invalid_request.
+         It is RECOMMENDED that the OP return an error_description
+         value identifying the invalid parameter value.
+    """
+    res = testclient.get(
+        "/oauth/authorize",
+        params=dict(
+            response_type="code",
+            client_id=trusted_client.client_id,
+            scope="openid profile",
+            nonce="somenonce",
+            prompt="create",
+        ),
+        status=400,
+    )
+    assert res.json == {
+        "error": "invalid_request",
+        "error_description": "prompt 'create' value is not supported",
+    }
+
+
+def test_prompt_create_not_logged(testclient, trusted_client, smtpd):
+    """
+    If prompt=create and user is not logged in,
+    then display the registration form.
+    Check that the user is correctly redirected to
+    the client page after the registration process.
+    """
+    testclient.app.config["ENABLE_REGISTRATION"] = True
+
+    res = testclient.get(
+        "/oauth/authorize",
+        params=dict(
+            response_type="code",
+            client_id=trusted_client.client_id,
+            scope="openid profile",
+            nonce="somenonce",
+            prompt="create",
+        ),
+    )
+
+    # Display the registration form
+    res = res.follow()
+    res.form["email"] = "foo@bar.com"
+    res = res.form.submit()
+
+    # Checks the registration mail is sent
+    assert len(smtpd.messages) == 1
+
+    # Simulate a click on the validation link in the mail
+    payload = RegistrationPayload(
+        creation_date_isoformat=datetime.datetime.now(
+            datetime.timezone.utc
+        ).isoformat(),
+        user_name="",
+        user_name_editable=True,
+        email="foo@bar.com",
+        groups=[],
+    )
+    registration_url = url_for(
+        "core.account.registration",
+        data=payload.b64(),
+        hash=payload.build_hash(),
+        _external=True,
+    )
+
+    # Fill the user creation form
+    res = testclient.get(registration_url)
+    res.form["user_name"] = "newuser"
+    res.form["password1"] = "password"
+    res.form["password2"] = "password"
+    res.form["family_name"] = "newuser"
+    res = res.form.submit()
+
+    assert res.flashes == [
+        ("success", "Your account has been created successfully."),
+    ]
+
+    # Return to the client
+    res = res.follow()
+    assert res.location.startswith(trusted_client.redirect_uris[0])
diff --git a/tests/oidc/test_client_admin.py b/tests/oidc/test_client_admin.py
index 6b42ff42..cfcef631 100644
--- a/tests/oidc/test_client_admin.py
+++ b/tests/oidc/test_client_admin.py
@@ -21,7 +21,7 @@ def test_client_list(testclient, client, logged_admin):
     res.mustcontain(client.client_name)
 
 
-def test_client_list_pagination(testclient, logged_admin, client, other_client):
+def test_client_list_pagination(testclient, logged_admin, client, trusted_client):
     res = testclient.get("/admin/client")
     res.mustcontain("2 items")
     clients = []
@@ -67,18 +67,18 @@ def test_client_list_bad_pages(testclient, logged_admin):
     )
 
 
-def test_client_list_search(testclient, logged_admin, client, other_client):
+def test_client_list_search(testclient, logged_admin, client, trusted_client):
     res = testclient.get("/admin/client")
     res.mustcontain("2 items")
     res.mustcontain(client.client_name)
-    res.mustcontain(other_client.client_name)
+    res.mustcontain(trusted_client.client_name)
 
     form = res.forms["search"]
     form["query"] = "other"
     res = form.submit()
 
     res.mustcontain("1 item")
-    res.mustcontain(other_client.client_name)
+    res.mustcontain(trusted_client.client_name)
     res.mustcontain(no=client.client_name)
 
 
@@ -144,7 +144,7 @@ def test_add_missing_fields(testclient, logged_admin):
     ) in res.flashes
 
 
-def test_client_edit(testclient, client, logged_admin, other_client):
+def test_client_edit(testclient, client, logged_admin, trusted_client):
     res = testclient.get("/admin/client/edit/" + client.client_id)
     data = {
         "client_name": "foobar",
@@ -162,7 +162,7 @@ def test_client_edit(testclient, client, logged_admin, other_client):
         "software_version": "1",
         "jwk": "jwk",
         "jwks_uri": "https://foo.bar/jwks.json",
-        "audience": [client.id, other_client.id],
+        "audience": [client.id, trusted_client.id],
         "preconsent": True,
         "post_logout_redirect_uris-0": "https://foo.bar/disconnected",
     }
@@ -196,12 +196,12 @@ def test_client_edit(testclient, client, logged_admin, other_client):
     assert client.software_version == "1"
     assert client.jwk == "jwk"
     assert client.jwks_uri == "https://foo.bar/jwks.json"
-    assert client.audience == [client, other_client]
+    assert client.audience == [client, trusted_client]
     assert not client.preconsent
     assert client.post_logout_redirect_uris == ["https://foo.bar/disconnected"]
 
 
-def test_client_edit_missing_fields(testclient, client, logged_admin, other_client):
+def test_client_edit_missing_fields(testclient, client, logged_admin, trusted_client):
     res = testclient.get("/admin/client/edit/" + client.client_id)
     res.forms["clientaddform"]["client_name"] = ""
     res = res.forms["clientaddform"].submit(name="action", value="edit")
@@ -255,7 +255,7 @@ def test_client_delete_invalid_client(testclient, logged_admin, client):
     )
 
 
-def test_client_edit_preauth(testclient, client, logged_admin, other_client):
+def test_client_edit_preauth(testclient, client, logged_admin, trusted_client):
     assert not client.preconsent
 
     res = testclient.get("/admin/client/edit/" + client.client_id)
@@ -275,7 +275,7 @@ def test_client_edit_preauth(testclient, client, logged_admin, other_client):
     assert not client.preconsent
 
 
-def test_client_edit_invalid_uri(testclient, client, logged_admin, other_client):
+def test_client_edit_invalid_uri(testclient, client, logged_admin, trusted_client):
     res = testclient.get("/admin/client/edit/" + client.client_id)
     res.forms["clientaddform"]["client_uri"] = "invalid"
     res = res.forms["clientaddform"].submit(status=200, name="action", value="edit")
diff --git a/tests/oidc/test_hybrid_flow.py b/tests/oidc/test_hybrid_flow.py
index e8bffc1a..911f7339 100644
--- a/tests/oidc/test_hybrid_flow.py
+++ b/tests/oidc/test_hybrid_flow.py
@@ -46,7 +46,7 @@ def test_oauth_hybrid(testclient, backend, user, client):
     assert res.json["name"] == "John (johnny) Doe"
 
 
-def test_oidc_hybrid(testclient, backend, logged_user, client, keypair, other_client):
+def test_oidc_hybrid(testclient, backend, logged_user, client, keypair, trusted_client):
     res = testclient.get(
         "/oauth/authorize",
         params=dict(
@@ -75,7 +75,7 @@ def test_oidc_hybrid(testclient, backend, logged_user, client, keypair, other_cl
     claims = jwt.decode(id_token, keypair[1])
     assert logged_user.user_name == claims["sub"]
     assert logged_user.formatted_name == claims["name"]
-    assert [client.client_id, other_client.client_id] == claims["aud"]
+    assert [client.client_id, trusted_client.client_id] == claims["aud"]
 
     res = testclient.get(
         "/oauth/userinfo",
diff --git a/tests/oidc/test_implicit_flow.py b/tests/oidc/test_implicit_flow.py
index 4cc3d945..567c5c10 100644
--- a/tests/oidc/test_implicit_flow.py
+++ b/tests/oidc/test_implicit_flow.py
@@ -50,7 +50,7 @@ def test_oauth_implicit(testclient, user, client):
     client.save()
 
 
-def test_oidc_implicit(testclient, keypair, user, client, other_client):
+def test_oidc_implicit(testclient, keypair, user, client, trusted_client):
     client.grant_types = ["token id_token"]
     client.token_endpoint_auth_method = "none"
 
@@ -88,7 +88,7 @@ def test_oidc_implicit(testclient, keypair, user, client, other_client):
     claims = jwt.decode(id_token, keypair[1])
     assert user.user_name == claims["sub"]
     assert user.formatted_name == claims["name"]
-    assert [client.client_id, other_client.client_id] == claims["aud"]
+    assert [client.client_id, trusted_client.client_id] == claims["aud"]
 
     res = testclient.get(
         "/oauth/userinfo",
@@ -104,7 +104,7 @@ def test_oidc_implicit(testclient, keypair, user, client, other_client):
 
 
 def test_oidc_implicit_with_group(
-    testclient, keypair, user, client, foo_group, other_client
+    testclient, keypair, user, client, foo_group, trusted_client
 ):
     client.grant_types = ["token id_token"]
     client.token_endpoint_auth_method = "none"
@@ -143,7 +143,7 @@ def test_oidc_implicit_with_group(
     claims = jwt.decode(id_token, keypair[1])
     assert user.user_name == claims["sub"]
     assert user.formatted_name == claims["name"]
-    assert [client.client_id, other_client.client_id] == claims["aud"]
+    assert [client.client_id, trusted_client.client_id] == claims["aud"]
     assert ["foo"] == claims["groups"]
 
     res = testclient.get(
diff --git a/tests/oidc/test_token_introspection.py b/tests/oidc/test_token_introspection.py
index adf149ab..c3334a6b 100644
--- a/tests/oidc/test_token_introspection.py
+++ b/tests/oidc/test_token_introspection.py
@@ -58,7 +58,7 @@ def test_token_invalid(testclient, client):
     assert {"active": False} == res.json
 
 
-def test_full_flow(testclient, logged_user, client, user, other_client):
+def test_full_flow(testclient, logged_user, client, user, trusted_client):
     res = testclient.get(
         "/oauth/authorize",
         params=dict(
@@ -103,7 +103,7 @@ def test_full_flow(testclient, logged_user, client, user, other_client):
         headers={"Authorization": f"Basic {client_credentials(client)}"},
         status=200,
     )
-    assert set(res.json["aud"]) == {client.client_id, other_client.client_id}
+    assert set(res.json["aud"]) == {client.client_id, trusted_client.client_id}
     assert res.json["active"]
     assert res.json["client_id"] == client.client_id
     assert res.json["token_type"] == token.type
diff --git a/tests/oidc/test_well_known.py b/tests/oidc/test_well_known.py
index 6ad2c2e2..cd7fea68 100644
--- a/tests/oidc/test_well_known.py
+++ b/tests/oidc/test_well_known.py
@@ -100,3 +100,9 @@ def test_openid_configuration(testclient):
         "userinfo_endpoint": "http://canaille.test/oauth/userinfo",
         "prompt_values_supported": ["none"],
     }
+
+
+def test_openid_configuration_prompt_value_create(testclient):
+    testclient.app.config["ENABLE_REGISTRATION"] = True
+    res = testclient.get("/.well-known/openid-configuration", status=200).json
+    assert "create" in res["prompt_values_supported"]