Between 1983 and 1991 we performed 212 endopyelotomies on 110 cases of primary and 102 of secondary obstruction of the ureteropelvic junction. Of the 189 patients in the series 89% have been followed for a minimum of 6 months postoperatively, 63% for more than 3 years (3 to 8-year followup). Our overall success rate has been 86% with little difference being detected between the success that we have obtained with primary and secondary obstructions (85% versus 86%). Other variables, such as patient age, sex or side of obstruction, have little bearing on the outcome of the procedure. Endopyelotomy is passing the test of time as a safe and reliable means to correct ureteropelvic junction obstruction. Endopyelotomy should be the first choice for the correction of ureteropelvic junction obstruction in most patients.