diff --git a/src/main/java/com/openisle/service/SearchService.java b/src/main/java/com/openisle/service/SearchService.java
index 517467058..14a692f8b 100644
--- a/src/main/java/com/openisle/service/SearchService.java
+++ b/src/main/java/com/openisle/service/SearchService.java
@@ -11,7 +11,9 @@ import lombok.RequiredArgsConstructor;
 import org.springframework.stereotype.Service;
 
 import java.util.List;
+import java.util.LinkedHashMap;
 import java.util.stream.Stream;
+import java.util.stream.Collectors;
 
 @Service
 @RequiredArgsConstructor
@@ -46,13 +48,29 @@ public class SearchService {
     public List<SearchResult> globalSearch(String keyword) {
         Stream<SearchResult> users = searchUsers(keyword).stream()
                 .map(u -> new SearchResult("user", u.getId(), u.getUsername()));
-        Stream<SearchResult> posts = searchPosts(keyword).stream()
-                .map(p -> new SearchResult("post", p.getId(), p.getTitle()));
-        Stream<SearchResult> titles = searchPostsByTitle(keyword).stream()
-                .map(p -> new SearchResult("post_title", p.getId(), p.getTitle()));
+
+        // Merge post results while removing duplicates between search by content
+        // and search by title
+        List<SearchResult> mergedPosts = Stream.concat(
+                    searchPosts(keyword).stream()
+                            .map(p -> new SearchResult("post", p.getId(), p.getTitle())),
+                    searchPostsByTitle(keyword).stream()
+                            .map(p -> new SearchResult("post_title", p.getId(), p.getTitle()))
+                )
+                .collect(java.util.stream.Collectors.toMap(
+                        SearchResult::id,
+                        sr -> sr,
+                        (a, b) -> a,
+                        java.util.LinkedHashMap::new
+                ))
+                .values()
+                .stream()
+                .toList();
+
         Stream<SearchResult> comments = searchComments(keyword).stream()
                 .map(c -> new SearchResult("comment", c.getId(), c.getContent()));
-        return Stream.concat(Stream.concat(Stream.concat(users, posts), titles), comments)
+
+        return Stream.concat(Stream.concat(users, mergedPosts.stream()), comments)
                 .toList();
     }
 
diff --git a/src/test/java/com/openisle/service/SearchServiceTest.java b/src/test/java/com/openisle/service/SearchServiceTest.java
new file mode 100644
index 000000000..19379cc82
--- /dev/null
+++ b/src/test/java/com/openisle/service/SearchServiceTest.java
@@ -0,0 +1,47 @@
+package com.openisle.service;
+
+import com.openisle.model.Post;
+import com.openisle.model.PostStatus;
+import com.openisle.repository.CommentRepository;
+import com.openisle.repository.PostRepository;
+import com.openisle.repository.UserRepository;
+import org.junit.jupiter.api.Test;
+import org.mockito.Mockito;
+
+import java.util.List;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+class SearchServiceTest {
+
+    @Test
+    void globalSearchDeduplicatesPosts() {
+        UserRepository userRepo = Mockito.mock(UserRepository.class);
+        PostRepository postRepo = Mockito.mock(PostRepository.class);
+        CommentRepository commentRepo = Mockito.mock(CommentRepository.class);
+        SearchService service = new SearchService(userRepo, postRepo, commentRepo);
+
+        Post post1 = new Post();
+        post1.setId(1L);
+        post1.setTitle("hello");
+        Post post2 = new Post();
+        post2.setId(2L);
+        post2.setTitle("world");
+
+        Mockito.when(postRepo.findByTitleContainingIgnoreCaseOrContentContainingIgnoreCaseAndStatus(
+                Mockito.anyString(), Mockito.anyString(), Mockito.eq(PostStatus.PUBLISHED)))
+                .thenReturn(List.of(post1));
+        Mockito.when(postRepo.findByTitleContainingIgnoreCaseAndStatus(Mockito.anyString(), Mockito.eq(PostStatus.PUBLISHED)))
+                .thenReturn(List.of(post1, post2));
+        Mockito.when(commentRepo.findByContentContainingIgnoreCase(Mockito.anyString()))
+                .thenReturn(List.of());
+        Mockito.when(userRepo.findByUsernameContainingIgnoreCase(Mockito.anyString()))
+                .thenReturn(List.of());
+
+        List<SearchService.SearchResult> results = service.globalSearch("h");
+
+        assertEquals(2, results.size());
+        assertEquals(1L, results.get(0).id());
+        assertEquals(2L, results.get(1).id());
+    }
+}