Despite modern advances in endovascular techniques, intraaneurysmal coil embolization may be associated with serious complications such as parent artery occlusion by thromboembolism and coil migration or incomplete treatment, which require surgery. We report 5 cases in which surgical interventions had been necessary following coil embolization with Guglielmi Detachable Coil, either due to incomplete aneurysm obliteration or acute complication of parent artery occlusion by coil migration and throm-boembolism. Surgical intervention include removal of the coils and clipping of the aneurysm. Immediate recanalization of the occluded artery by use of intra-arterial thrombolytics and surgery is very important. The role of neurosurgical management in the care of the patients suffering from unsuccessful endovascular therapy of aneurysm is demonstrated.