We took 7 dogs to undergo thorough autotransplant of the ureter as an autologous nonvascularized free graft, after having obtained good results with rats. The steps followed in these 7 dogs were the removal of a 10- to 12-cm segment of the ureter and the replantation of the same segment to the same animal. We must point out that both anastomoses were performed with interrupted sutures. Although some complications such as stenosis occurred, urographic studies showed that some animals kept their renal function for over 8 months after autotransplantation. Using contrast, we were able to observe the ureter. Similarly, we observed peristaltic waves on the ureters which were always dilated. Histologic studies showed preservation of the ureteral layers with hyperplasia of the ureteral mucosa, greater or lesser degree of submucosal fibrosis, and a variable degree of hyperplasia or muscular atrophy. Extensive areas of bone metaplasia were observed in some animals.