A follow-up study of 46 cases of isolated coarctation of the aorta (age at surgical treatment 1 to 48 years) is presented. The late postoperative blood pressure was the higher the later surgical treatment was carried out. When surgical treatment was carried out at an age of more than 14 years, an increase of the residual hypertension rate was observed. A relatively low rate of residual hypertension can be expected after correction at about 6 to 10 years. Surgical treatment in infancy does not seem to have beneficial effects since according to other reports correction at this age does not reduce the residual hypertension rate essentially. Apart from the elevated residual hypertension rate surgical treatment at an advanced age generally has a lowering effect on blood pressure values.