diff --git a/backend/api/main.py b/backend/api/main.py
index d12e26d..25987de 100644
--- a/backend/api/main.py
+++ b/backend/api/main.py
@@ -1,13 +1,17 @@
 import sqlite3
 
 from fastapi import FastAPI, status
+from fastapi.responses import JSONResponse
 
 from backend.adapters.sqlite import create_db
 from backend.api.model import StudentModel, TribeModel
 from backend.model.student import Student
 from backend.model.tribe import Tribe
 from backend.repository.student_sqlite_repository import StudentSQLiteRepository
-from backend.repository.tribe_sqlite_repository import TribeSQLiteRepository
+from backend.repository.tribe_sqlite_repository import (
+    TribeRepositoryError,
+    TribeSQLiteRepository,
+)
 
 # from sqlalchemy import create_engine
 # from sqlalchemy.orm import clear_mappers, sessionmaker
@@ -33,7 +37,13 @@ app = FastAPI()
 async def post_tribe(item: TribeModel):
     tribe = Tribe(**item.dict())
 
-    tribe_repo.add(tribe)
+    try:
+        tribe_repo.add(tribe)
+    except TribeRepositoryError:
+        return JSONResponse(
+            status_code=status.HTTP_409_CONFLICT,
+            content=f"The tribe {tribe.name} already exists",
+        )
     conn.commit()
 
     return tribe.to_dict()
diff --git a/backend/repository/tribe_sqlite_repository.py b/backend/repository/tribe_sqlite_repository.py
index fd26984..b7d2c72 100644
--- a/backend/repository/tribe_sqlite_repository.py
+++ b/backend/repository/tribe_sqlite_repository.py
@@ -2,11 +2,21 @@ from backend.model.tribe import Tribe
 from backend.repository.abstract_repository import AbstractRepository
 
 
+class TribeRepositoryError(Exception):
+    pass
+
+
 class TribeSQLiteRepository(AbstractRepository):
     def __init__(self, conn) -> None:
         self.conn = conn
 
     def add(self, tribe: Tribe) -> None:
+        tribes = self.list()
+        if tribe.name in map(lambda x: x.name, tribes):
+            raise TribeRepositoryError(
+                f"The tribe {tribe.name} already exists. Can't add it"
+            )
+
         self.conn.execute(
             """
         INSERT INTO tribes(name, level) VALUES (?, ?)
diff --git a/tests/e2e/test_api.py b/tests/e2e/test_api.py
index 2702021..2ecf119 100644
--- a/tests/e2e/test_api.py
+++ b/tests/e2e/test_api.py
@@ -22,6 +22,19 @@ def test_api_post_tribe():
     }
 
 
+@pytest.mark.usefixtures("restart_api")
+@pytest.mark.usefixtures("clean_db")
+def test_api_post_tribe_already_exists():
+    data = {"name": "Pioupiou", "level": "2nd"}
+
+    url = config.get_api_url()
+    r = requests.post(f"{url}/tribes", json=data)
+    r = requests.post(f"{url}/tribes", json=data)
+
+    assert r.status_code == 409
+    assert r.json() == f"The tribe {data['name']} already exists"
+
+
 @pytest.mark.usefixtures("restart_api")
 @pytest.mark.usefixtures("clean_db")
 def test_api_post_list_tribe():
@@ -57,3 +70,19 @@ def test_api_post_student():
     assert r.json()["name"] == "zart"
     assert r.json()["tribe_name"] == tribe.name
     assert r.json()["id"]
+
+
+@pytest.mark.usefixtures("restart_api")
+@pytest.mark.usefixtures("clean_db")
+def test_api_post_student():
+    url = config.get_api_url()
+    tribe = build_tribes(1)[0]
+    requests.post(f"{url}/tribes", json=tribe.to_dict())
+
+    data = {"name": "zart", "tribe_name": tribe.name}
+    r = requests.post(f"{url}/students", json=data)
+
+    assert r.status_code == 201
+    assert r.json()["name"] == "zart"
+    assert r.json()["tribe_name"] == tribe.name
+    assert r.json()["id"]