diff --git a/.github/workflows/_integration_test.yml b/.github/workflows/_integration_test.yml
index 0c680c55..cd3c062b 100644
--- a/.github/workflows/_integration_test.yml
+++ b/.github/workflows/_integration_test.yml
@@ -48,6 +48,7 @@ jobs:
           GOOGLE_API_KEY: ${{ secrets.GOOGLE_API_KEY }}
           GOOGLE_SEARCH_API_KEY: ${{ secrets.GOOGLE_SEARCH_API_KEY }}
           GOOGLE_CSE_ID: ${{ secrets.GOOGLE_CSE_ID }}
+          GOOGLE_VERTEX_AI_WEB_CREDENTIALS: ${{ secrets.GOOGLE_VERTEX_AI_WEB_CREDENTIALS }}
         run: |
           make integration_tests
 
diff --git a/.github/workflows/_release.yml b/.github/workflows/_release.yml
index 3ca3374f..acd18b0f 100644
--- a/.github/workflows/_release.yml
+++ b/.github/workflows/_release.yml
@@ -174,6 +174,7 @@ jobs:
           GOOGLE_API_KEY: ${{ secrets.GOOGLE_API_KEY }}
           GOOGLE_SEARCH_API_KEY: ${{ secrets.GOOGLE_SEARCH_API_KEY }}
           GOOGLE_CSE_ID: ${{ secrets.GOOGLE_CSE_ID }}
+          GOOGLE_VERTEX_AI_WEB_CREDENTIALS: ${{ secrets.GOOGLE_VERTEX_AI_WEB_CREDENTIALS }}
         run: make integration_tests
         working-directory: ${{ inputs.working-directory }}
 
diff --git a/libs/vertexai/langchain_google_vertexai/_base.py b/libs/vertexai/langchain_google_vertexai/_base.py
index cc6c85a5..dd377f96 100644
--- a/libs/vertexai/langchain_google_vertexai/_base.py
+++ b/libs/vertexai/langchain_google_vertexai/_base.py
@@ -121,7 +121,10 @@ def validate_params_base(cls, values: dict) -> Any:
     @model_validator(mode="after")
     def validate_project(self) -> Any:
         if self.project is None:
-            self.project = initializer.global_config.project
+            if self.credentials and hasattr(self.credentials, "project_id"):
+                self.project = self.credentials.project_id
+            else:
+                self.project = initializer.global_config.project
         return self
 
     @property
diff --git a/libs/vertexai/tests/integration_tests/test_chat_models.py b/libs/vertexai/tests/integration_tests/test_chat_models.py
index 2fffb601..d3384d02 100644
--- a/libs/vertexai/tests/integration_tests/test_chat_models.py
+++ b/libs/vertexai/tests/integration_tests/test_chat_models.py
@@ -2,6 +2,7 @@
 
 import base64
 import json
+import os
 from typing import List, Optional, cast
 
 import pytest
@@ -11,6 +12,7 @@
     Content,
     Part,
 )
+from google.oauth2 import service_account
 from langchain_core.messages import (
     AIMessage,
     AIMessageChunk,
@@ -912,3 +914,12 @@ def test_langgraph_example() -> None:
         tools=[{"function_declarations": [add_declaration, multiply_declaration]}],
     )
     assert isinstance(step2, AIMessage)
+
+
+def test_init_from_credentials_obj() -> None:
+    credentials_dict = json.loads(os.environ["GOOGLE_VERTEX_AI_WEB_CREDENTIALS"])
+    credentials = service_account.Credentials.from_service_account_info(
+        credentials_dict
+    )
+    llm = ChatVertexAI(model="gemini-1.5-flash", credentials=credentials)
+    llm.invoke("how are you")