SummaryWe performed a quantitative systematic review of randomised, controlled trials that compared remifentanil to short-acting opioids (fentanyl, alfentanil, or sufentanil) for general anaesthesia. Eighty-five trials were identified and these included a total of 13 057 patients. Intra-operatively, remifentanil was associated with clinical signs of deeper analgesia and anaesthesia, such as fewer responses to noxious stimuli (relative risk 0.65, 95% CI 0.48-0.87), more frequent episodes of bradycardia (1.46, 1.04-2.05), more hypotension (1.68, 1.36-2.07) and less hypertension (0.60, 0.46-0.78). Postoperatively, remifentanil was associated with faster recovery (difference in extubation time of )2.03, 9.5% CI, )2.92 to