Objectives. To investigate and compare the effectiveness of three analgesic protocols for pain management during extracorporeal shock wave lithotripsy (ESWL) in a prospective, randomized clinical trial. Methods. Seventy-four patients were randomized into three groups before ESWL; group A (n = 23) received 10 mg morphine sulfate (MS), group B (n = 25) 60 mg ketorolac tromethamine (KT), and group C (n = 26) topical 2.5% lidocaine/prilocaine gel (Emla). Each method of pain management during ESWL was assessed using a standard 10-point linear pain scale and by the requirement for supplemental analgesia during treatment. Supplemental analgesia was administered intravenously using a patient-controlled analgesic pump. The results were compared between the three groups, as were such parameters as body habitus, stone burden, stone location, number of shock waves, and the presence of ureteral stents. Results. Pain severity averaged 4.6 points on the pain scale for the three groups combined. Pain tended to be more severe in group C (5.4) than in group A (4.3) or group B (4.1); however, the differences were not statistically significant (P >0.05). The amount of supplemental analgesia was similar in all three groups. Stone burden, stone location, and number of shock waves did not influence the severity of pain or analgesic requirement during ESWL. The analgesic requirement was significantly less in patients with ureteral stents (n = 32) than in patients without (n = 42), averaging 10 mg versus 24 mg MS, respectively (P = 0.01). KT was not associated with adverse events such as bleeding. MS was more likely to cause oversedation and nausea or vomiting, necessitating naloxone and antiemetic therapy, respectively. Conclusions. The use of KT was safe and effective for premedication before ESWL; patients receiving KT before ESWL reported lower pain scores and required less supplemental analgesia requirement than those who received MS or Emla; however, the differences were not statistically significant. Patients receiving Emla recorded the highest pain scores. Patients with ureteral stents had lower pain scores and required less supplemental analgesia. UROLOGY 54: 625-628, 1999. (C) 1999, Elsevier Science Inc.