We have assessed if recovery times after morphine or fentanyl, given before terminating remifentanil anaesthesia with isoflurane or propofol, are compromised. We studied patients undergoing elective, major abdominal surgery, allocated randomly to receive remifentanil and isoflurane (n = 277) or remifentanil and propofol (n = 274) anaesthesia. Twenty-five minutes before the end of surgery, patients received fentanyl 0.15 mg or morphine 15 mg in a randomized, double-blind manner followed by a second dose (fentanyl 0.05 mg, morphine 7 mg) for moderate or severe pain in recovery. Recovery was rapid and at an Aldrete score > or = 9 (median 12-15 min), 42-51% of patients reported none or mild pain. However, 26-35% of patients reported severe pain and > 90% required a second dose of opioid within 21-27 min after anaesthesia.