In a prospective controlled randomised trial on patients undergoing operative repair of fractured neck of femur via a lateral incision, the postoperative analgesic requirements of one group of patients who received a lateral cutaneous nerve block were compared with a second group who received no block. The former group were found to need significantly less intramuscular pethidine in the first 24 hours, and 44% required no supplementary analgesia whatsoever during this period. The time to first dose of opioid in the remainder was greatly increased. No untoward sequelae associated with the nerve block were seen.