The safety, effectiveness and duration of a percutaneous ilioinguinal-iliohypogastric nerve block with 10 ml 0.5% bupivacaine, as a method for postoperative analgesia, were studied prospectively in adult patients undergoing unilateral inguinal herniorrhaphy under spinal anesthesia. Group I (n = 20) blocked patients were compared with Group II (n = 25), non-blocked control patients. A blinded observer assessed pain scores and analgesic requirements after surgery. Group I patients had less pain at 3, 6, 24 and 48 hours after surgery and also required less analgesics during the first two postoperative days. This technique appears to be a simple and safe method for providing effective and long-lasting postoperative analgesia following inguinal hernia repair in adults.