diff --git a/backend/src/service/service_service.rs b/backend/src/service/service_service.rs
index 5fc1889..ba2bb1a 100644
--- a/backend/src/service/service_service.rs
+++ b/backend/src/service/service_service.rs
@@ -66,23 +66,6 @@ impl ServiceService {
             None => return Err("errors.service_not_found".to_string()),
         }
 
-        // Verify user belongs to organization
-        // We use a simplified check here assuming the controller has validated the admin's rights.
-        // But we must ensure the target user is in the same organization to avoid cross-org assignments.
-        // Actually, we can check if the user is in the organisation_user table for this org.
-
-        /*
-           Note: I need to make sure UserRepository is accessible.
-           If UserRepository is not public or methods are not public, I might have issues.
-           Assuming they are public based on previous context.
-        */
-
-        // For now, let's just update the user service
-        // Strict check: User must be in the organisation
-        // Since we don't have direct access to is_member_of_organisation easily without importing,
-        // I will trust the controller to send valid data or add the check if I can import UserRepository.
-
-        // Adding the check:
         let is_member = UserRepository::is_member_of_organisation(pool, user_id, organisation_id)
             .await
             .map_err(|e| format!("db_error: {}", e))?;
diff --git a/backend/tests/service_service_tests.rs b/backend/tests/service_service_tests.rs
new file mode 100644
index 0000000..bdc063d
--- /dev/null
+++ b/backend/tests/service_service_tests.rs
@@ -0,0 +1,235 @@
+use sqlx::MySqlPool;
+use backend::service::service_service::ServiceService;
+
+#[sqlx::test]
+async fn devrait_creer_un_service(pool: MySqlPool) {
+    // GIVEN
+    let org_id = 1;
+    let nom_service = "Nouveau Service Test";
+
+    // WHEN
+    let services = ServiceService::create_service(&pool, org_id, nom_service).await.unwrap();
+
+    // THEN
+    assert!(services.iter().any(|s| s.nom == nom_service));
+}
+
+#[sqlx::test]
+async fn devrait_retourner_erreur_si_nom_vide(pool: MySqlPool) {
+    // GIVEN
+    let org_id = 1;
+    let nom_service = "   ";
+
+    // WHEN
+    let result = ServiceService::create_service(&pool, org_id, nom_service).await;
+
+    // THEN
+    assert!(result.is_err());
+    assert_eq!(result.unwrap_err(), "errors.validation_service_name_required");
+}
+
+#[sqlx::test]
+async fn devrait_retourner_erreur_si_service_existe_deja(pool: MySqlPool) {
+    // GIVEN
+    let org_id = 1;
+    let nom_service = "Service Existant";
+
+    // WHEN
+    ServiceService::create_service(&pool, org_id, nom_service).await.unwrap();
+    let result = ServiceService::create_service(&pool, org_id, nom_service).await;
+
+    // THEN
+    assert!(result.is_err());
+    assert_eq!(result.unwrap_err(), "errors.service_exists");
+}
+
+#[sqlx::test]
+async fn devrait_recuperer_services_organisation(pool: MySqlPool) {
+    // GIVEN
+    let org_id = 1;
+
+    // WHEN
+    let services = ServiceService::get_organisation_services(&pool, org_id).await.unwrap();
+
+    // THEN
+    assert!(!services.is_empty());
+}
+
+#[sqlx::test]
+async fn devrait_recuperer_services_utilisateur(pool: MySqlPool) {
+    // GIVEN
+    let org_id = 1;
+    let user_id = 1; // Un utilisateur existant dans l'organisation 1
+
+    let services_crees = ServiceService::create_service(&pool, org_id, "Service user test").await.unwrap();
+    let service_id = services_crees.into_iter().find(|s| s.nom == "Service user test").unwrap().id;
+
+    ServiceService::assign_user_to_service(&pool, user_id, service_id, org_id).await.unwrap();
+
+    // WHEN
+    let user_services = ServiceService::get_services_by_user_id(&pool, user_id).await.unwrap();
+
+    // THEN
+    assert!(user_services.iter().any(|s| s.id == service_id));
+}
+
+#[sqlx::test]
+async fn devrait_assigner_et_desassigner_utilisateur(pool: MySqlPool) {
+    // GIVEN
+    let org_id = 1;
+    let user_id = 1; // Utilisateur existant dans l'organisation 1
+    let services = ServiceService::get_organisation_services(&pool, org_id).await.unwrap();
+    let service_id = services.first().expect("Devrait avoir au moins un service").id;
+
+    // WHEN - Assigner
+    let assign_result = ServiceService::assign_user_to_service(&pool, user_id, service_id, org_id).await;
+
+    // THEN
+    assert!(assign_result.is_ok());
+
+    // WHEN - Désassigner
+    let unassign_result = ServiceService::unassign_user_from_service(&pool, user_id, org_id).await;
+
+    // THEN
+    assert!(unassign_result.is_ok());
+}
+
+#[sqlx::test]
+async fn devrait_retourner_erreur_si_assignation_service_inexistant(pool: MySqlPool) {
+    // GIVEN
+    let org_id = 1;
+    let user_id = 1;
+
+    // WHEN
+    let result = ServiceService::assign_user_to_service(&pool, user_id, 99999, org_id).await;
+
+    // THEN
+    assert!(result.is_err());
+    assert_eq!(result.unwrap_err(), "errors.service_not_found");
+}
+
+#[sqlx::test]
+async fn devrait_retourner_erreur_si_assignation_service_autre_organisation(pool: MySqlPool) {
+    // GIVEN
+    let org1 = 1;
+    let org2 = 2; // Suppose qu'il y a une organisation 2 ou on utilisera un id bidon
+    let user_id = 1;
+    let services = ServiceService::create_service(&pool, org1, "Service Org 1").await.unwrap();
+    let service_id = services.into_iter().find(|s| s.nom == "Service Org 1").unwrap().id;
+
+    // WHEN
+    let result = ServiceService::assign_user_to_service(&pool, user_id, service_id, org2).await;
+
+    // THEN
+    assert!(result.is_err());
+    assert_eq!(result.unwrap_err(), "errors.service_not_in_organisation");
+}
+
+#[sqlx::test]
+async fn devrait_retourner_erreur_si_assignation_utilisateur_autre_organisation(pool: MySqlPool) {
+    // GIVEN
+    let org_id = 1;
+    let user_id = 99999; // Utilisateur inexistant
+    let services = ServiceService::create_service(&pool, org_id, "Service User Inexistant").await.unwrap();
+    let service_id = services.into_iter().find(|s| s.nom == "Service User Inexistant").unwrap().id;
+
+    // WHEN
+    let result = ServiceService::assign_user_to_service(&pool, user_id, service_id, org_id).await;
+
+    // THEN
+    assert!(result.is_err());
+    assert_eq!(result.unwrap_err(), "errors.user_not_in_organisation");
+}
+
+#[sqlx::test]
+async fn devrait_retourner_erreur_si_desassignation_utilisateur_autre_organisation(pool: MySqlPool) {
+    // GIVEN
+    let org_id = 1;
+    let user_id = 99999;
+
+    // WHEN
+    let result = ServiceService::unassign_user_from_service(&pool, user_id, org_id).await;
+
+    // THEN
+    assert!(result.is_err());
+    assert_eq!(result.unwrap_err(), "errors.user_not_in_organisation");
+}
+
+#[sqlx::test]
+async fn devrait_supprimer_service(pool: MySqlPool) {
+    // GIVEN
+    let org_id = 1;
+    let services = ServiceService::create_service(&pool, org_id, "Service a supprimer").await.unwrap();
+    let service_id = services.into_iter().find(|s| s.nom == "Service a supprimer").unwrap().id;
+
+    // WHEN
+    let delete_result = ServiceService::delete_service(&pool, service_id, org_id).await;
+
+    // THEN
+    assert!(delete_result.is_ok());
+
+    let remaining_services = ServiceService::get_organisation_services(&pool, org_id).await.unwrap();
+    assert!(!remaining_services.iter().any(|s| s.id == service_id));
+}
+
+#[sqlx::test]
+async fn devrait_retourner_erreur_si_suppression_service_inexistant(pool: MySqlPool) {
+    // GIVEN
+    let org_id = 1;
+
+    // WHEN
+    let result = ServiceService::delete_service(&pool, 99999, org_id).await;
+
+    // THEN
+    assert!(result.is_err());
+    assert_eq!(result.unwrap_err(), "errors.service_not_found");
+}
+
+#[sqlx::test]
+async fn devrait_retourner_erreur_si_suppression_service_autre_organisation(pool: MySqlPool) {
+    // GIVEN
+    let org1 = 1;
+    let org2 = 2; // Simulation d'une tentative de suppression depuis une autre org
+    let services = ServiceService::create_service(&pool, org1, "Service Org 1 a ne pas suppr").await.unwrap();
+    let service_id = services.into_iter().find(|s| s.nom == "Service Org 1 a ne pas suppr").unwrap().id;
+
+    // WHEN
+    let result = ServiceService::delete_service(&pool, service_id, org2).await;
+
+    // THEN
+    assert!(result.is_err());
+    assert_eq!(result.unwrap_err(), "errors.service_not_in_organisation");
+}
+
+#[sqlx::test]
+async fn devrait_retourner_db_error_si_erreur_bdd(pool: MySqlPool) {
+    // GIVEN - Fermer le pool pour forcer une erreur de base de données (PoolClosed)
+    pool.close().await;
+
+    // WHEN
+    let res_create = ServiceService::create_service(&pool, 1, "Test Db Error").await;
+    let res_get_org = ServiceService::get_organisation_services(&pool, 1).await;
+    let res_get_user = ServiceService::get_services_by_user_id(&pool, 1).await;
+    let res_delete = ServiceService::delete_service(&pool, 1, 1).await;
+    let res_assign = ServiceService::assign_user_to_service(&pool, 1, 1, 1).await;
+    let res_unassign = ServiceService::unassign_user_from_service(&pool, 1, 1).await;
+
+    // THEN
+    assert!(res_create.is_err());
+    assert!(res_create.unwrap_err().starts_with("db_error:"));
+
+    assert!(res_get_org.is_err());
+    assert!(res_get_org.unwrap_err().starts_with("db_error:"));
+
+    assert!(res_get_user.is_err());
+    assert!(res_get_user.unwrap_err().starts_with("db_error:"));
+
+    assert!(res_delete.is_err());
+    assert!(res_delete.unwrap_err().starts_with("db_error:"));
+
+    assert!(res_assign.is_err());
+    assert!(res_assign.unwrap_err().starts_with("db_error:"));
+
+    assert!(res_unassign.is_err());
+    assert!(res_unassign.unwrap_err().starts_with("db_error:"));
+}