A double-blind randomised study was performed to assess the analgesic effect of epidural diamorphine, administered with bupivacaine, on primigravid women in labour. Fifty patients received 0.25% bupivacaine 10 ml via the epidural catheter as their initial dose; patients in Group 1 received diamorphine 5 mg with the bupivacaine. A 0.1% bupivacaine infusion was started at 10 minutes and bolus doses of bupivacaine were given if required. There was a significant reduction in rate of bupivacaine administration, pain scores at 20 and 30 minutes, number of supplements required, and degree of motor blockade in the diamorphine group.