Acute type A aortic dissection was surgically treated in 33 patients aged 20-65 years, all critically ill on admission to hospital. Transthoracic echocardiography revealed pericardiac tamponade in eight cases of extreme emergency, indicating surgery without need of additional imaging. Transesophageal echocardiography provided a definitive diagnosis in 16 cases, with excellent reliability and no false positive findings. Composite graft replacement with button technique was used in 24 patients and other methods of repair in nine. The perioperative mortality was 12% (4/33) and the late mortality 7% (2/29). The actuarial 5-year survival rate was 73%. No aortic root reoperation was required during follow-up for a mean of 4 years. Transesophageal echocardiography proved to be an accurate tool for speedy diagnosis of acute type A aortic dissection and open composite graft replacement with button technique highly satisfactory treatment, avoiding late aortic root problems.