A series of 262 observed cases of aneurysm of the thoracic aorta is examined in which 216 cases of surgical correction were performed between 1974 and 1987. Dissecting aneurysms and post-traumatic pseudoaneurysms, although of different aetiology and morbid anatomy, are also included since the surgical technique adopted is similar in all groups. Clinically different aspects of acute and chronic lesions are analyzed. Of all preoperative examinations, angiography is preferred as it gives the most precise definition of the aortic lesion. This is especially necessary in the case of acute dissection or rupture of thoracic aorta although the role of CAT scan is becoming progressively more important. In cases of aortic dissection with massive aortic valve insufficiency, the substitution of the ascending aorta and aortic valve with reimplantation of coronary arteries, in accordance with Bentall's technique is also indicated. The improvement in surgical results is emphasized, since surgical mortality has decreased from 30.6% to 22% in the last eight years. This is due to improvement in surgical technique, to extra corporeal circulation and myocardial protection.