diff --git a/prothsync/src/main/java/com/prothsync/prothsync/service/FollowService.java b/prothsync/src/main/java/com/prothsync/prothsync/service/FollowService.java
index f0e63e3..4b48cdb 100644
--- a/prothsync/src/main/java/com/prothsync/prothsync/service/FollowService.java
+++ b/prothsync/src/main/java/com/prothsync/prothsync/service/FollowService.java
@@ -7,6 +7,7 @@
 import com.prothsync.prothsync.entity.user.Follow;
 import com.prothsync.prothsync.entity.user.User;
 import com.prothsync.prothsync.exception.BusinessException;
+import com.prothsync.prothsync.exception.FollowErrorCode;
 import com.prothsync.prothsync.exception.UserErrorCode;
 import com.prothsync.prothsync.global.PageResponse;
 import com.prothsync.prothsync.repository.repository.FollowRepository;
@@ -33,6 +34,10 @@ public class FollowService {
 
     @Transactional
     public FollowResponseDTO toggleFollow(Long followerId, Long followingId) {
+        if (followerId.equals(followingId)) {
+            throw new BusinessException(FollowErrorCode.CANNOT_FOLLOW_SELF);
+        }
+
         User follower = findUserOrThrow(followerId);
         User following = findUserOrThrow(followingId);