We report on eight kidney-allografted patients treated for delayed ureteral obstruction between January 1986 and January 1987. In all cases, standard endourological dilation was performed using a balloon catheter, and this was followed by insertion of a pigtail stent. All eight cases showed improvement 1 month after dilation (decrease in creatinine and caliceal dilation). At 6 months, renal function had deteriorated in six patients but remained good in two. One of the six patients was redilated with apparently good results. The remaining five were operated on using their own ureter. We conclude that while internal drainage helps in distinguishing between obstruction and other causes of creatinine increase, antegrade dilation is the treatment of choice for delayed ureteral obstruction.