Forty patients who were to have total hip replacement were randomly allocated to two groups. One group received intramuscular pethidine (30 mg) alone for postoperative analgesia in the first 24 h, the other received transcutaneous stimulation (TES) and pethidine as necessary. The use of pethidine was compared in the two groups under standardised conditions of time, operative and anaesthetic techniques. There was less pethidine used in the TES group. The technique is simple and non-invasive and can be used continuously. It was well accepted by both patients and staff. The electrodes must be prepared carefully and placed accurately. An ideal stimulation effect was often achieved by similar patterns of stimulating parameters.