diff --git a/tests/litellm/proxy/middleware/test_prometheus_auth_middleware.py b/tests/litellm/proxy/middleware/test_prometheus_auth_middleware.py
new file mode 100644
index 0000000000..b72ff75002
--- /dev/null
+++ b/tests/litellm/proxy/middleware/test_prometheus_auth_middleware.py
@@ -0,0 +1,129 @@
+import json
+import os
+import sys
+
+import pytest
+from fastapi.testclient import TestClient
+
+sys.path.insert(
+    0, os.path.abspath("../../..")
+)  # Adds the parent directory to the system path
+
+
+import pytest
+from fastapi import FastAPI
+from fastapi.responses import JSONResponse
+from fastapi.testclient import TestClient
+
+import litellm
+from litellm.proxy._types import SpecialHeaders
+from litellm.proxy.middleware.prometheus_auth_middleware import PrometheusAuthMiddleware
+
+
+# Fake auth functions to simulate valid and invalid auth behavior.
+async def fake_valid_auth(request, api_key):
+    # Simulate valid authentication: do nothing (i.e. pass)
+    return
+
+
+async def fake_invalid_auth(request, api_key):
+    print("running fake invalid auth", request, api_key)
+    # Simulate invalid auth by raising an exception.
+    raise Exception("Invalid API key")
+
+
+from litellm.proxy.auth.user_api_key_auth import user_api_key_auth
+
+
+@pytest.fixture
+def app_with_middleware():
+    """Create a FastAPI app with the PrometheusAuthMiddleware and dummy endpoints."""
+    app = FastAPI()
+    # Add the PrometheusAuthMiddleware to the app.
+    app.add_middleware(PrometheusAuthMiddleware)
+
+    @app.get("/metrics")
+    async def metrics():
+        return {"msg": "metrics OK"}
+
+    # Also allow /metrics/ (trailing slash)
+    @app.get("/metrics/")
+    async def metrics_slash():
+        return {"msg": "metrics OK"}
+
+    @app.get("/chat/completions")
+    async def chat():
+        return {"msg": "chat completions OK"}
+
+    @app.get("/embeddings")
+    async def embeddings():
+        return {"msg": "embeddings OK"}
+
+    return app
+
+
+def test_valid_auth_metrics(app_with_middleware, monkeypatch):
+    """
+    Test that a request to /metrics (and /metrics/) with valid auth headers passes.
+    """
+    # Enable auth on metrics endpoints.
+    litellm.require_auth_for_metrics_endpoint = True
+    # Patch the auth function to simulate a valid authentication.
+    monkeypatch.setattr(
+        "litellm.proxy.middleware.prometheus_auth_middleware.user_api_key_auth",
+        fake_valid_auth,
+    )
+
+    client = TestClient(app_with_middleware)
+    headers = {SpecialHeaders.openai_authorization.value: "valid"}
+
+    # Test for /metrics (no trailing slash)
+    response = client.get("/metrics", headers=headers)
+    assert response.status_code == 200, response.text
+    assert response.json() == {"msg": "metrics OK"}
+
+    # Test for /metrics/ (with trailing slash)
+    response = client.get("/metrics/", headers=headers)
+    assert response.status_code == 200, response.text
+    assert response.json() == {"msg": "metrics OK"}
+
+
+def test_invalid_auth_metrics(app_with_middleware, monkeypatch):
+    """
+    Test that a request to /metrics with invalid auth headers fails with a 401.
+    """
+    litellm.require_auth_for_metrics_endpoint = True
+    # Patch the auth function to simulate a failed authentication.
+    monkeypatch.setattr(
+        "litellm.proxy.middleware.prometheus_auth_middleware.user_api_key_auth",
+        fake_invalid_auth,
+    )
+
+    client = TestClient(app_with_middleware)
+    headers = {SpecialHeaders.openai_authorization.value: "invalid"}
+
+    response = client.get("/metrics", headers=headers)
+    assert response.status_code == 401, response.text
+    assert "Unauthorized access to metrics endpoint" in response.text
+
+
+def test_no_auth_metrics_when_disabled(app_with_middleware, monkeypatch):
+    """
+    Test that when require_auth_for_metrics_endpoint is False, requests to /metrics
+    bypass the auth check.
+    """
+    litellm.require_auth_for_metrics_endpoint = False
+
+    # To ensure auth is not run, patch the auth function with one that will raise if called.
+    def should_not_be_called(*args, **kwargs):
+        raise Exception("Auth should not be called")
+
+    monkeypatch.setattr(
+        "litellm.proxy.middleware.prometheus_auth_middleware.user_api_key_auth",
+        should_not_be_called,
+    )
+
+    client = TestClient(app_with_middleware)
+    response = client.get("/metrics")
+    assert response.status_code == 200, response.text
+    assert response.json() == {"msg": "metrics OK"}