Involvement of the ureters (rigid and segmented) and bladder was seen in a 6-year-old child whose clinical lesions were typical of Henoch-Schoenlein purpura. Infrapelvic left uretic stenosis developed secondarily whilst the other lesions disappeared. Histological study and in particular cutaneous and renal immunofluorescence made it possible to eliminate the possible diagnosis of polyarteritis nodosa, and to confirm that of Henoch-Schoenlein purpura. An ischaemic vasculitis was the cause of the ureteric and bladder lesions, and of the progression to stenosis. The existence of this possibility should lead to routine examination to detect such lesions. Sequential radiological studies are necessary whenever such lesions are recognised.