Domperidone (R 33812) was injected i.v. for the prevention of nausea and vomiting in a total of 395 cytostatic treatment courses in 172 patients. The total dose ranged from 1 to 40 mg and was given in one or several doses. Even after the administration of severely emetic substances, vomiting and nausea were largely prevented in hospitalized patients, but the results were rather poor in ambulatory patients. In all of the cytostatic treatment schedules very favourable results were obtained.