Arthroscopic shoulder surgery can result in severe postoperative pain. A variety of methods have been used to control pain in postoperative period and the results are variable. The purpose of this study was to compare the relative analgesic efficacies of the postoperative intraarticular infusion of ropivacaine, ropivacaine/fentanyl, and ropivacaine/fentanyl/ketorolac after arthroscopic shoulder surgery. Thirty patients undergoing arthroscopic shoulder surgery under general anesthesia were randomly assigned to three groups. At the end of surgery, 0.5% ropivacaine 20 ml was infused into the articular space and a continuous infusion catheter was inserted into intraarticular operated site. After surgery, continuous infusion of 0.5% ropivacaine 100 ml (Group 1, n = 10), 0.5% ropivacaine 100 ml including fentanyl 10 microg/kg (Group 2, n = 10), or 0.5% ropivacaine 100 ml including fentanyl 10 microgram/kg and ketorolac 150 mg (Group 3, n = 10) was started through catheter at rate of 2 ml/hr with bolus dose of 0.5 ml with a lock out time of 15 minutes for 2 days. The level of pain was assessed using a visual analogue scale (VAS) postoperative 2, 6, 12, 24 and 48 hours and the amounts of supplemental analgesics were recorded. The VAS was significantly lower after 2, 6, 12 hours in Group 2 than in Group 1. In Group 3, the VAS was significantly lower all hours than in the other two groups. The combination of fentanyl and ketorolac with ropivacaine did provide better postoperative analgesia than the other groups after arthroscopic shoulder surgery.