Gluteal aneurysms, whether true or false, are exceptional. They represent less than 1% of all aneurysms and develop within the superior or inferior gluteal arteries, being branches of the internal iliac artery. We report here the case of a 35-year-old patient with Marfan syndrome in whom annuloaortic ectasia and Barlow's disease with mitral valve insufficiency successively developed followed by a gluteal false aneurysm, which led us to investigate the etiologic mechanism of the patient's conditions. The gluteal aneurysm was successfully treated by selective embolization, which would appear to be the elective therapeutic approach for these lesions.