We describe a case of accidental subdural block, after attempted extradural puncture for Caesarean section. Fractionation of the local anaesthetic dose led to avoidance of more serious complications. Subdural fentanyl and a continuous low-dose subdural infusion were used satisfactorily for intraoperative management and postoperative analgesia. As little as 0.5 ml of bupivacaine, hourly, provided satisfactory analgesia over a 15-h period.