Five urologic complications in the posttransplantation period were performed in a case material of 68 renal transplantations in children, performed at the Transplantation Center in Lille, Northern France over the period 1981-July 1990. Three patients had ureteral stenosis (4.4 per cent), 1 urinary fistula (1.5 per cent) and 1 calculosis (1.5 per cent). All these cases are described and illustrated with figures. Comparing the results with those reported from other leading transplantation centers, the authors point to the low incidence of urologic complications in their case material (7.3 per cent). This encouraging result is attributed to the adequate selection of recipients, preliminary removal of accompanying urologic anomalies, early transplantation (82 per cent before the end of the second year after initiation of hemodialysis), as well as to precise explantation and transplantation.