Forty two TUU have been performed from 1974 to 1986 in children and young adults: the youngest was 10 years, the oldest 26. The mean follow-up has been more than 5 years: 23 bladder exstrophies, 12 neurogenic bladders, 5 mega-ureters and 2 retroperitoneal tumors. TUU were performed after failure of uretero-cysto-neostomies (8/42) ou uretero-sigmoid reimplantation (19/42). The technique with details about drainage (16/42) is described. In 5 cases, complications appeared early: 3 fistulae, 2 sweelings of the anastomosis. tests done 3 months after the operation did not show any other complication in relation with the TUU. Nevertheless one reflux and 3 stenoses of the end of the recipient ureter caused dilatation of two upper urinary tracts. During the long term follow-up, it was necessary to perform 2 nephrectomies of the donor ureter and 5 operations on the end of the recipient ureter. These complications were independant of the TUU. The final result of TUU was excellent.