Between 1970 and 1986, 40 patients had surgical treatment for dissection of the ascending aorta at the London Chest Hospital. The overall hospital mortality was 27.5%. Preoperative renal impairment and age greater than or equal to 60 years were both associated with a significantly increased hospital mortality. In the long term one patient was lost to follow up. There have been two late deaths among the remaining 28 patients (mean follow up 4.4 years). The functional state of the survivors is good, with only three having any cardiac disability.