Between 1978 and 1992, 70 patients were operated for type B aortic dissection (tear in the descending aorta without involvement of the ascending aorta). 15/70 (21%) patients had an acute dissection (onset of symptoms < 24 h), 19/70 (27%) a subacute dissection (onset of symptoms < 14 days), and 36/70 (51) a chronic dissection (onset of symptoms > 14 days). The indications for surgery in cases of acute dissection were: hematothorax, oliguria, leg ischemia and persistent pain. Persistent hypertension was an additional indication in cases of subacute dissection. In large majority (93%) of chronic dissections the indication for surgery was enlarged aortic diameter. In 86% (60/70) graft replacement of the aorta was performed, in 6% (4/70) extra-anatomic bypass, in 3% (2/70) fenestration, in 3% (2/70) thrombendarterectomy, in 3% (2/70). The overall mortality was 17% (12/70); 27% of acute dissection, 26% for subacute dissection, and 8% for chronic dissection. The morbidity for acute dissection was 73%, of subacute dissection 43%, and of chronic dissection 12%. The most frequent complications were: leg ischemia (8 patients), renal failure (4 patients), paraparesis (4 patients) and sepsis (2 patients). No paraparesis was encountered in surgery of the chronic dissection. Conservative treatment was tried in all acute B-dissections, with surgical therapy being reserved for complications of the dissection, such as rupture, such as rupture, risk of rupture (hematothorax, large aortic diameter resp. expansion, persistent hypertension, persistent pain) or ischemia of distal vascular beds. Long-term survival for chronic type B dissections is good. Strong control of risk factors (hypertension) is essential.