A patient not known in advance to have the sleep apnoea syndrome (SAS) was administered a combined epidural-general anaesthetic for a proposed radical prostatectomy. After surgery which had to be discontinued due to extensive tumoural spread, morphine 5 mg was administered through the epidural catheter for analgesia. Severe respiratory depression occurred eight hours later and was successfully reversed by repeated injections of naloxone. The potential danger of epidural morphine administration to SAS patients is discussed.