diff --git a/src/main/java/com/dnd/snappy/domain/mission/repository/MissionRepository.java b/src/main/java/com/dnd/snappy/domain/mission/repository/MissionRepository.java
index 6fb15ed..a877dee 100644
--- a/src/main/java/com/dnd/snappy/domain/mission/repository/MissionRepository.java
+++ b/src/main/java/com/dnd/snappy/domain/mission/repository/MissionRepository.java
@@ -1,14 +1,29 @@
 package com.dnd.snappy.domain.mission.repository;
 
+import com.dnd.snappy.domain.mission.dto.response.LeaderMeetingMissionDetailResponseDto;
 import com.dnd.snappy.domain.mission.entity.Mission;
 
 import java.util.List;
 import java.util.Optional;
+
 import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.data.jpa.repository.Query;
+import org.springframework.data.repository.query.Param;
 
 public interface MissionRepository extends JpaRepository<Mission, Long> {
 
     Optional<Mission> findByIdAndMeetingId(Long id, Long meetingId);
 
     List<Mission> findAllByMeetingId(Long meetingId);
-}
+
+    @Query("""
+    SELECT new com.dnd.snappy.domain.mission.dto.response.LeaderMeetingMissionDetailResponseDto(m.id, m.content, 
+        CASE WHEN mp.id IS NOT NULL THEN TRUE ELSE FALSE END) 
+    FROM Mission m 
+    LEFT JOIN MissionParticipant mp ON mp.mission.id = m.id 
+    JOIN Participant p ON p.meeting.id = m.meeting.id 
+    WHERE p.id = :participantId AND p.role = 'LEADER' AND m.meeting.id = :meetingId
+    """)
+    List<LeaderMeetingMissionDetailResponseDto> findLeaderMeetingMissions(@Param("meetingId") Long meetingId, @Param("participantId") Long participantId);
+
+}
\ No newline at end of file
diff --git a/src/main/java/com/dnd/snappy/domain/mission/service/MissionDetailService.java b/src/main/java/com/dnd/snappy/domain/mission/service/MissionDetailService.java
index 6177239..c62fe9f 100644
--- a/src/main/java/com/dnd/snappy/domain/mission/service/MissionDetailService.java
+++ b/src/main/java/com/dnd/snappy/domain/mission/service/MissionDetailService.java
@@ -7,7 +7,6 @@
 import com.dnd.snappy.domain.mission.dto.response.LeaderMeetingMissionDetailResponseDto;
 import com.dnd.snappy.domain.mission.dto.response.MeetingMissionDetailResponseDto;
 import com.dnd.snappy.domain.mission.entity.Mission;
-import com.dnd.snappy.domain.mission.repository.MissionParticipantRepository;
 import com.dnd.snappy.domain.mission.repository.MissionRepository;
 import lombok.RequiredArgsConstructor;
 import org.springframework.stereotype.Service;
@@ -23,7 +22,6 @@ public class MissionDetailService {
     private final MissionRepository missionRepository;
     private final MeetingRepository meetingRepository;
     private final MissionValidationService missionValidationService;
-    private final MissionParticipantRepository missionParticipantRepository;
 
     @Transactional(readOnly = true)
     public List<MeetingMissionDetailResponseDto> findMeetingMissions(Long meetingId, Long participantId) {
@@ -40,23 +38,7 @@ public List<LeaderMeetingMissionDetailResponseDto> findLeaderMeetingMissions(Lon
         findByMeetingIdOrThrow(meetingId);
         missionValidationService.validateIsLeader(participantId, meetingId);
 
-        List<Mission> missions = missionRepository.findAllByMeetingId(meetingId);
-
-        return missions.stream()
-                .map(mission -> {
-                    boolean hasParticipants = hasParticipants(mission.getId());
-                    return new LeaderMeetingMissionDetailResponseDto(
-                            mission.getId(),
-                            mission.getContent(),
-                            hasParticipants
-                    );
-                })
-                .collect(Collectors.toList());
-    }
-
-    @Transactional
-    public boolean hasParticipants(Long missionId) {
-        return missionParticipantRepository.existsByMissionId(missionId);
+        return missionRepository.findLeaderMeetingMissions(meetingId, participantId);
     }
 
     private Meeting findByMeetingIdOrThrow(Long meetingId) {
diff --git a/src/test/java/com/dnd/snappy/domain/mission/service/MissionDetailServiceTest.java b/src/test/java/com/dnd/snappy/domain/mission/service/MissionDetailServiceTest.java
index f265480..bd48bd5 100644
--- a/src/test/java/com/dnd/snappy/domain/mission/service/MissionDetailServiceTest.java
+++ b/src/test/java/com/dnd/snappy/domain/mission/service/MissionDetailServiceTest.java
@@ -13,8 +13,6 @@
 import com.dnd.snappy.domain.mission.dto.response.MeetingMissionDetailResponseDto;
 import com.dnd.snappy.domain.mission.entity.Mission;
 import com.dnd.snappy.domain.mission.exception.MissionErrorCode;
-
-import com.dnd.snappy.domain.mission.repository.MissionParticipantRepository;
 import com.dnd.snappy.domain.mission.repository.MissionRepository;
 
 import java.util.List;
@@ -43,9 +41,6 @@ class MissionDetailServiceTest {
     @Mock
     private MissionValidationService missionValidationService;
 
-    @Mock
-    private MissionParticipantRepository missionParticipantRepository;
-
     @DisplayName("미션 목록을 조회한다.")
     @Test
     void findMeetingMissions() {
@@ -92,8 +87,14 @@ void findLeaderMeetingMissions() {
 
         given(meetingRepository.findById(meetingId)).willReturn(Optional.of(meeting));
         doNothing().when(missionValidationService).validateIsLeader(participantId, meetingId);
-        given(missionRepository.findAllByMeetingId(meetingId)).willReturn(missions);
-        given(missionParticipantRepository.existsByMissionId(anyLong())).willReturn(false);
+
+        given(missionRepository.findLeaderMeetingMissions(meetingId, participantId)).willReturn(
+                List.of(
+                        new LeaderMeetingMissionDetailResponseDto(1L, "미션 내용 1", false),
+                        new LeaderMeetingMissionDetailResponseDto(2L, "미션 내용 2", false),
+                        new LeaderMeetingMissionDetailResponseDto(3L, "미션 내용 3", false)
+                )
+        );
 
         // when
         List<LeaderMeetingMissionDetailResponseDto> result = missionDetailService.findLeaderMeetingMissions(meetingId, participantId);