Scopolamine, applicable without severe side effects as a transdermal therapeutic system (TTS), has a pronounced postoperative antiemetic effect. In one publication there was found even a 50% reduction of emetic symptoms compared with placebo. In this study TTS-Scopolamine was compared with a single dose of 7.5 mg Droperidol in a group of 40 Patients undergoing cholecystectomy under standardised balanced anesthesia. After cholecystectomy patients are very much inclined for postoperative nausea and vomiting since it is an abdominal operation and it is more often necessary in women than in men. In this randomized, one-side-blind study the antinausea and antiemetic effect of transdermal Scopolamine was insufficient and significantly less than with Droperidol. In the Droperidol-group there were 45% of patients without emetic symptoms, in the Scopolamine-group only 15%. Vomiting occurred in 25% of patients in the Droperidol-group and in 50% of patients in the Scopolamine-group. Unfavourable CNS-side-effects could not be found either with transdermal scopolamine or with Droperidol. As favourable side-effects there was found a more even postoperative blood-pressure-curve in the Droperidol-group and a better scoring of preoperative sleep in the Scopolamine-group. Overall there is need for an exact indication for transdermal Scopolamine as a postoperative antiemetic. In this study Droperidol turned out to be a much stronger antiemetic for patients undergoing cholecystectomy.