diff --git a/backend/tests/test_stream_create.py b/backend/tests/test_stream_create.py
new file mode 100644
index 0000000..150c9d8
--- /dev/null
+++ b/backend/tests/test_stream_create.py
@@ -0,0 +1,33 @@
+import unittest
+from datetime import datetime
+
+from sqlalchemy.ext.asyncio import async_sessionmaker, create_async_engine
+
+from database import Base
+from services.stream_service import StreamService
+
+
+class StreamCreateTest(unittest.IsolatedAsyncioTestCase):
+    async def asyncSetUp(self):
+        self.engine = create_async_engine("sqlite+aiosqlite:///:memory:")
+        async with self.engine.begin() as connection:
+            await connection.run_sync(Base.metadata.create_all)
+        self.session_factory = async_sessionmaker(self.engine, expire_on_commit=False)
+
+    async def asyncTearDown(self):
+        await self.engine.dispose()
+
+    async def test_create_stream_accepts_frontend_iso_timestamp(self):
+        payload = {
+            "title": "Create flow regression",
+            "description": None,
+            "cover_url": None,
+            "scheduled_at": "2026-08-12T21:49:12.000Z",
+        }
+
+        async with self.session_factory() as session:
+            stream = await StreamService(session).create_stream(**payload)
+
+            self.assertEqual(stream.title, payload["title"])
+            self.assertIsInstance(stream.scheduled_at, datetime)
+            self.assertEqual(stream.scheduled_at.isoformat(), "2026-08-12T21:49:12")