Objective To evaluate the efficacy and safety of transdermal fentanyl path ( Durogesic, Xian Janssen) in patients with moderate to severe chronic non-cancer pain. Methods This open prospective study was approved by the Ethic committee of the hospital. After obtaining written informed consent we studied 46 ASA I - H patients (24 male, 22 female), aged 36-82 yr, suffering from moderate to severe chronic non-cancer pain. Durogesic 25 fxg/h was used. The patch and the site of application were changed every 3 days. The dose was adjusted to the level of pain reduction and side effects. The treatment was maintained for 2-4 weeks. The pain intensity measured using VAS, quality of life including appetite, mental state and sleep etc and side effects were recorded.Results Thirty-eight of the 46 patients completed the trial. The other 8 patients withdrew from the trial because of side effects. Durogesic significantly decreased pain (P