diff --git a/src/google/adk/tools/discovery_engine_search_tool.py b/src/google/adk/tools/discovery_engine_search_tool.py
index 0e771ece4f..1ac77db23d 100644
--- a/src/google/adk/tools/discovery_engine_search_tool.py
+++ b/src/google/adk/tools/discovery_engine_search_tool.py
@@ -17,6 +17,7 @@
 from typing import Any
 from typing import Optional
 
+from google.api_core import client_options as client_options_lib
 from google.api_core.exceptions import GoogleAPICallError
 import google.auth
 from google.cloud import discoveryengine_v1beta as discoveryengine
@@ -37,6 +38,9 @@ def __init__(
       search_engine_id: Optional[str] = None,
       filter: Optional[str] = None,
       max_results: Optional[int] = None,
+      client_options: Optional[
+          Union[client_options_lib.ClientOptions, dict]
+      ] = None,
   ):
     """Initializes the DiscoveryEngineSearchTool.
 
@@ -73,7 +77,8 @@ def __init__(
 
     credentials, _ = google.auth.default()
     self._discovery_engine_client = discoveryengine.SearchServiceClient(
-        credentials=credentials
+        client_options=client_options,
+        credentials=credentials,
     )
 
   def discovery_engine_search(
diff --git a/tests/unittests/tools/test_discovery_engine_search_tool.py b/tests/unittests/tools/test_discovery_engine_search_tool.py
index d10da252c7..983d3295c5 100644
--- a/tests/unittests/tools/test_discovery_engine_search_tool.py
+++ b/tests/unittests/tools/test_discovery_engine_search_tool.py
@@ -76,6 +76,14 @@ def test_init_with_data_store_specs_without_search_engine_id_raises_error(
           data_store_id="test_data_store", data_store_specs=[{"id": "123"}]
       )
 
+  def test_init_with_client_options(self):
+    """Test initialization with client_options"""
+    tool = DiscoveryEngineSearchTool(
+        data_store_id="test_data_store",
+        client_options={"api_endpoint": "test-discoveryengine"},
+    )
+    assert tool._discovery_engine_client._api_endpoint == "test-discoveryengine"
+
   @mock.patch(
       "google.cloud.discoveryengine_v1beta.SearchServiceClient",
   )