diff --git a/src/chat/dto/chatroom.dto.js b/src/chat/dto/chatroom.dto.js
index 383a96f..64584e6 100644
--- a/src/chat/dto/chatroom.dto.js
+++ b/src/chat/dto/chatroom.dto.js
@@ -21,6 +21,7 @@ export class ChatroomListResponseDto {
     this.artist_profile_image = room.artist.profileImage;
     this.commission_id = room.commission.id;
     this.commission_title = room.commission.title;
+    this.commission_thumbnail = room.commission.thumbnail || null;
     // 이미지가 있으면 이미지 URL, 없으면 텍스트 content
     const lastMsg = room.chatMessages[0];
     this.last_message = lastMsg?.imageUrl || lastMsg?.content || null;
diff --git a/src/chat/service/chatroom.service.js b/src/chat/service/chatroom.service.js
index b4480bb..ef8e260 100644
--- a/src/chat/service/chatroom.service.js
+++ b/src/chat/service/chatroom.service.js
@@ -49,16 +49,23 @@ export const ChatroomService = {
 
   async getChatroomsByUserId(dto) {
     const user = await UserRepository.findUserById(dto.userId);
-    if (!user) {
-      throw new UserNotFoundError({ userId: dto.userId });
-    }
+    if (!user) throw new UserNotFoundError({ userId: dto.userId });
 
     const chatrooms = await ChatroomRepository.findChatroomsByUser(dto.userId);
-    console.log(dto.accountId)
 
+    // thumbnail 한 번에 조회
+    const commissionIds = chatrooms.map(r => r.commission.id);
+    const images = await CommissionRepository.findImagesByCommissionId(commissionIds);
+    const thumbnailMap = Object.fromEntries(images.map(img => [img.targetId.toString(), img.imageUrl]));
+
+    // DTO 생성
     const result = [];
     for (const room of chatrooms) {
+      room.commission.thumbnail = thumbnailMap[room.commission.id.toString()] || null;
+
+      // 방마다 unreadCount 조회
       const unreadCount = await ChatRepository.countUnreadMessages(room.id, dto.accountId);
+
       result.push(new ChatroomListResponseDto(room, unreadCount));
     }
 
diff --git a/src/commission/service/commission.service.js b/src/commission/service/commission.service.js
index 8a64840..88f9337 100644
--- a/src/commission/service/commission.service.js
+++ b/src/commission/service/commission.service.js
@@ -56,35 +56,30 @@ export const CommissionService = {
    * S3 이미지 업로드 처리
    */
   async uploadRequestImage(file) {
-    try {
-      // 1. 파일 존재 여부 확인
-      if (!file) {
-        throw new ImageUploadFailedError({ reason: '파일이 업로드되지 않았습니다' });
-      }
-
-      // 2. 파일 크기 검증
-      if (file.size > 10 * 1024 * 1024) {
-        throw new FileSizeExceededError({ fileSize: file.size });
-      }
+    // 1. 파일 존재 여부 확인
+    if (!file) {
+      throw new ImageUploadFailedError({ reason: '파일이 업로드되지 않았습니다' });
+    }
 
-      // 3. 파일 확장자 검증
-      const ext = path.extname(file.originalname).toLowerCase().replace('.', '');
-      if (!['jpeg', 'jpg', 'png'].includes(ext)) {
-        throw new UnsupportedImageFormatError({ fileType: file.mimetype });
-      }
+    // 2. 파일 크기 검증
+    if (file.size > 10 * 1024 * 1024) {
+      throw new FileSizeExceededError({ fileSize: file.size });
+    }
 
-      // 4. S3 업로드 (requests 폴더에 저장)
-      const imageUrl = await uploadToS3(file.buffer, 'requests', ext);
+    // 3. 파일 확장자 검증
+    const ext = path.extname(file.originalname).toLowerCase().replace('.', '');
+    if (!['jpeg', 'jpg', 'png'].includes(ext)) {
+      throw new UnsupportedImageFormatError({ fileType: file.mimetype });
+    }
 
-      return {
-        image_url: imageUrl,
-        file_size: file.size,
-        file_type: file.mimetype
-      };
+    // 4. S3 업로드
+    const imageUrl = await uploadToS3(file.buffer, 'requests', ext);
 
-    } catch (error) {
-      throw error;
-    }
+    return {
+      image_url: imageUrl,
+      file_size: file.size,
+      file_type: file.mimetype
+    };
   },
 
   /**
diff --git a/src/common/swagger/chat.json b/src/common/swagger/chat.json
index 0ecc87b..9e237e1 100644
--- a/src/common/swagger/chat.json
+++ b/src/common/swagger/chat.json
@@ -115,6 +115,7 @@
                           "artist_profile_image": { "type": "string", "example": "https://example.com/artist1.png" },
                           "commission_id": { "type": "string", "example": "1" },
                           "commission_title": { "type": "string", "example": "테스트 커미션 글" },
+                          "commission_thumbnail": { "type": ["string", "null"], "example": "https://example.com/sample-thumbnail.png" },
                           "last_message": { "type": ["string", "null"], "example": null },
                           "last_message_time": { "type": ["string", "null"], "format": "date-time", "example": null },
                           "has_unread": { "type": "integer", "example": 0 }