OBJECTIVE--To study early and late mortality after surgical correction of coarctation of the aorta. DESIGN--Data on 223 patients operated on at the Westminster Hospital, London, between 1946 and 1981, were collected and updated by questionnaire. PARTICIPANTS--All 223 patients recorded as undergoing operation for aortic coarctation up to the end of 1981. Fifteen of 197 survivors were lost to follow up; most of them were patients from overseas. OUTCOME AND RESULTS--The early mortality (within one month of operation) was 12% overall, 2.6% for elective surgery, and 0% for the 77 patients undergoing surgery since 1968. Survivors were followed up for a total of 3288 patient years; in 27 follow up lasted more than 30 years. In a few it reached 40 years. Twenty two patients died during this period, 18 from causes that could be attributed to coarctation or its repair. Mortality was highest more than 20 years after the operation. CONCLUSION--Repair increased life expectancy in patients with aortic coarctation. Late problems caused by persistent hypertension or recoarctation became apparent in long term survivors. The increased risk of late mortality associated with the duration of preoperative hypertension was not statistically significant. There were no deaths from cerebrovascular accidents. (In an earlier necropsy series cerebrovascular accidents accounted for 11.8% of deaths.) The incidence of deaths from aneurysms resembled that in the earlier necropsy series.