The authors reviewed, from a urological standpoint, the records of 400 patients undergoing aorto-bifemoral bypass between 1967 and 1980. Stenosing or aneurysmal lesions of the renal arteries were present in 106 patients, i.e. 26.5% of cases. 7% of the patients had previous pathology (2 lithiasis, 4 hydronephrosis and one non-functioning kidney). All the operations consisted of a bypass inserted posterior to the peritoneum and ureters. 39 patients (9.7%) underwent simultaneous surgery on the renal artery or vein, or the kidney, Amongst a total of 12% deaths, 1.5% were of renal causes. The postoperative urological morbidity was 24.9% being dominated by infectious lesions (16%) and ureteric lesions (5%). The majority of ureteric lesions took the form of progressive distension of the excretory apparatus. The presence of an indwelling urethral catheter was considered to be the most important factor in infection. The authors feel that it is essential to visualise the urinary tract at the time of angiographic investigation of aortoiliac disease. Amongst 18 cases of progressive dilatation of the upper urinary tract after such vascular surgery, only 3 underwent operation. Nevertheless, intravenous urography is an essential part of postoperative surveillance after surgery of this sort. Only 15% of their patients had undergone IVU and amongst them 18 were found to have a hydronephrosis.