Ultrasonic energy has not been previously used for surgical cutting and coagulating. Work in our laboratory has led to the development of an ultrasonically activated scalpel that safely and effectively cuts and coagulates tissue in animals. The purpose of this study was to determine if ultrasonic energy can replace monopolar electrosurgery in human laparoscopic surgery. Two hundred consecutive patients underwent laparoscopic cholecystectomy with the ultrasonically activated scalpel. The scalpel was the sole energy form in 98 of the first 100 patients, and in all of the last 100 patients. There were no common duct injuries, reoperations, or mortality. No patient had more than a 3-g drop in hemoglobin or transfusion. The ultrasonically activated scalpel is a safe and effective energy form for cutting and coagulating tissue during laparoscopic cholecystectomy in humans. The absence of need of monopolar electrosurgery combined with hemostatic effectiveness supports the concept that the ultrasonically activated scalpel can replace electrosurgery for laparoscopic cholecystectomy.