diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/RustAxumServerCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/RustAxumServerCodegen.java
index 9bf2762fbb66..725708a1a9a4 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/RustAxumServerCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/RustAxumServerCodegen.java
@@ -429,6 +429,14 @@ public CodegenOperation fromOperation(String path, String httpMethod, Operation
         CodegenOperation op = super.fromOperation(path, httpMethod, operation, servers);
 
         String underscoredOperationId = underscore(op.operationId);
+        ArrayList<MethodOperation> pathMethods = pathMethodOpMap.get(path);
+
+        // Prevent multiple declarations of the same operation
+        if (pathMethods != null && pathMethods.stream().anyMatch(pathMethod ->
+                pathMethod.operationID.equals(underscoredOperationId))) {
+            return op;
+        }
+
         op.vendorExtensions.put("x-operation-id", underscoredOperationId);
         op.vendorExtensions.put("x-uppercase-operation-id", underscoredOperationId.toUpperCase(Locale.ROOT));
 
diff --git a/modules/openapi-generator/src/test/java/org/openapitools/codegen/rust/RustAxumServerCodegenTest.java b/modules/openapi-generator/src/test/java/org/openapitools/codegen/rust/RustAxumServerCodegenTest.java
new file mode 100644
index 000000000000..83c94e44d0ed
--- /dev/null
+++ b/modules/openapi-generator/src/test/java/org/openapitools/codegen/rust/RustAxumServerCodegenTest.java
@@ -0,0 +1,35 @@
+package org.openapitools.codegen.rust;
+
+import org.openapitools.codegen.DefaultGenerator;
+import org.openapitools.codegen.TestUtils;
+import org.openapitools.codegen.config.CodegenConfigurator;
+import org.testng.annotations.Test;
+
+import java.io.File;
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.List;
+
+import static org.openapitools.codegen.TestUtils.linearize;
+
+public class RustAxumServerCodegenTest {
+    @Test
+    public void testPreventDuplicateOperationDeclaration() throws IOException {
+        Path target = Files.createTempDirectory("test");
+        final CodegenConfigurator configurator = new CodegenConfigurator()
+                .setGeneratorName("rust-axum")
+                .setInputSpec("src/test/resources/3_1/issue_21144.yaml")
+                .setSkipOverwrite(false)
+                .setOutputDir(target.toAbsolutePath().toString().replace("\\", "/"));
+        List<File> files = new DefaultGenerator().opts(configurator.toClientOptInput()).generate();
+        files.forEach(File::deleteOnExit);
+        Path outputPath = Path.of(target.toString(), "/src/server/mod.rs");
+        String routerSpec = linearize("Router::new() " +
+                ".route(\"/api/test\", " +
+                "delete(test_delete::<I, A, E, C>).post(test_post::<I, A, E, C>) ) " +
+                ".with_state(api_impl)");
+        TestUtils.assertFileExists(outputPath);
+        TestUtils.assertFileContains(outputPath, routerSpec);
+    }
+}
\ No newline at end of file
diff --git a/modules/openapi-generator/src/test/resources/3_1/issue_21144.yaml b/modules/openapi-generator/src/test/resources/3_1/issue_21144.yaml
new file mode 100644
index 000000000000..749cc5ab38f1
--- /dev/null
+++ b/modules/openapi-generator/src/test/resources/3_1/issue_21144.yaml
@@ -0,0 +1,33 @@
+openapi: 3.0.0
+info:
+  title: "test"
+  version: "0.1.1"
+  description: "test"
+paths:
+  /api/test:
+    delete:
+      operationId: "test_delete"
+      description: "Delete method"
+      responses:
+        204:
+          description: "delete"
+      security:
+        - apiKey: []
+    post:
+      tags:
+        - firsttag
+        - secondtag
+        - thirdtag
+      operationId: "test_post"
+      description: "Post method"
+      responses:
+        201:
+          description: "post"
+      security:
+        - apiKey: []
+components:
+  securitySchemes:
+    apiKey:
+      type: apiKey
+      name: X-API-Key
+      in: header
\ No newline at end of file