Percutaneous renal surgery is routine therapy for a number of renal pathologies, It is a technique not without complications, often serious ones, of which the worst is bleeding, We reviewed our experience of the incidence, etiology, and management of this serious complication to determine a protocol of treatment that will minimize the consequences. Between 1984 and 1996, we carried out 976 percutaneous operations for reno-calix stones, pyeloureteral junction stenosis, neoplasia of the renal pelvis, diagnosis, and ureteral prostheses. In all cases, the percutaneous access was achieved through a lower calix in the posterior axillary line with the patient in a prone position, The lithotripsy was performed with ultrasound and balistic energy lithotripters, Antegrade endopyelotomy was performed according to our technique, At the end of the procedure, a nephrostomy tube was positioned, 24F for lithotripsy and 16F for endopyelotomy, The nephrostomy tube was removed after 24 to 48 hours. In this series, 146 patients (15%) presented significant perioperative bleeding. In 97 cases (10%), this complication was resolved with the repositioning of the nephrostomy tube, bedrest in a supine position, and observation, whereas in 49 cases (5%), clamping of the nephrostomy tube for 24 hours was necessary, In 56 patients (5.7%), two blood transfusions were necessary, and three patients (0.3%) had bleeding 10, 12, and 20 days after the operation, which was resolved by embolization of the lacerated vessel.