4 cases of circumcaval ureter presenting in childhood are reported. A review of the literature reveals that most cases recieve attention only later in life at a time when ureteric changes are not so readily reversible. A study of the course of the ureter reveals that 2 forms can be distinguished: a common Type I with a slter reveals that 2 forms can be distinguished: a common Type I with a low loop and kinking of the proximal ureter producing obstruction and a rare Type II with a high loop where there is no kinking and no obstruction. Ureteric remodelling on the ordinary principles formulated for congenital obstructions can give good results.