The development and treatment of false aneurysm after cardiovascular intervention is discussed. At the Cardiovascular Surgical Clinic of Semmelweis Medical University (Budapest) 6900 reconstruction operations were performed. Ninety-five false aneurysms were operated on. According to the cause leading to the complication the patients are classified into 8 groups. To treat the false aneurysm 14 types of operation were carried out. Operative mortality was 12.6 per cent, but the outcome was successful in 70 per cent of the patients. The technique of surgical treatment is described. A review of the literature is presented.