The stent size necessary to promote optimal ureteral healing after an endoureterotomy is not known. We compared healing of an endoureterotomy over a 7F indwelling ureteral stent with healing over a 14F endopyelotomy stent. A midureteral stricture was created in each of 25 anesthetized female minipigs using an electrified stone basket passed retrograde. Six weeks later, the stricture was incised with a 24F cutting balloon device. Twenty pigs were randomized to receive a 7F or a 14F stent; four control pigs received neither incisions nor stents. At 1 week, a radiograph was performed to confirm proper stent position, and the stents were removed. At 3 months, a retrograde ureterogram was performed, and the ureters were examined grossly and harvested for histologic studies. Two of the ten pigs in each study group developed a recurrent stricture. The use of a 14F stent provided no advantage over the use of a smaller, more easily positioned 7F stent.