Purpose: The duration of stenting after endoureterotomy is a controversial issue. An even more basic question, however, is whether stent placement is needed at all. We performed a porcine study to address this question. Methods: A unilateral midureteral stricture was created in 20 minipigs. Six weeks later, 15 pigs underwent endoureterotomy. In 10 animals, a 7F ureteral stent was placed for 1 week. Five pigs remained unstented. Three months later, all 20 ureters were studied radiographically and were harvested. Results: Three of 5 control animals and 2 of 10 stented animals had strictures. In the unstented study group, all 5 animals had a nonobstructing dilation at the site of endoureterotomy. This was corroborated by a normal furosemide washout renal scan in all 3 animals so tested. Conclusions: The result of unstented endoureterotomy in the porcine model suggests that, after endoureterotomy of secondary midureteral strictures, stenting may be unnecessary.