Domperidone was compared with placebo in a multicenter double-blind study of 116 patients (15 to 80 years) with postoperative vomiting. After vomiting had occurred, the patients received either domperidone 10 mg or placebo IV. Patients were then followed for at least 6 hours or until a 2nd injection of domperidone 10 mg from an open supply was needed. The period of time until an additional injection was registered and compared between the 2 treatment groups. Fifty-nine percent of the placebo patients needed a 2nd injection before the end of the 6-hour follow-up, compared with only 35% of the domperidone patients (p<0.05). When a 2nd injection was required, the time elapsed before it was needed was longer (p = 0.01) in the domperidone group (median 150 minutes) than in the placebo one (median 120 minutes). There were no significant side-effects.