BACKGROUND: Postoperative shoulder-tip pain (STP) frequently occurs following laparoscopic surgery, In an attempt to abrogate this complication we prospectively evaluated the efficacy of intraoperative irrigation of the diaphragm with bupivacaine, METHODS: One hundred and five consecutive patients undergoing laparoscopic surgery were prospectively randomized to treatment or control groups. Treatment group (B, n = 55) received irrigation with 10 mt 0.5% bupivacaine in 500 mt saline and control group (A, n = 50) received an equal Volume of normal saline. Each dome of the diaphragm was irrigated with 250 mt of either solution at the end of surgery. Laparoscopic procedures performed included cholecystectomy (n = 63), Nissen fundoplication (n = 21), appendicectomy (n = 7), hernia repair (n = 4), and diagnostic laparoscopy (n = 10). Patients' anesthesia and perioperative analgesia were standardized. STP was recorded on a visual analogue pain scale (VAPS) in the recovery room immediately following surgery and at 4, 10, and 24 hours thereafter. RESULTS: The overall incidence of STP in patients undergoing laparoscopic procedures was approximately 24%. Twenty-one patients (42%) in the control group and 4 patients (7%) in the treatment group complained of shoulder pain during the recording period (P = 0.003), Mean STP scores as recorded on VAPS were significantly lower in the bupivacaine group than in the control group from 4 to 24 hours after surgery (P <0.01). Postoperative analgesia requirements were also significantly reduced in those patients receiving bupivacaine irrigation (P <0.04), CONCLUSION: Intraperitoneal irrigation with bupivacaine to both hemidiaphragms at the end of surgery significantly reduces both frequency and intensity of STP following laparoscopic procedures thus reducing patient morbidity. (C) 1998 by Excerpta Medica, Inc.