Abstract Study objective To compare the frequency of postoperative emetic symptoms and side effects in pediatric strabismus surgery using four doses of droperidol. Design Randomized, blinded study. Setting University eye institute. Patients 82 ASA physical status I and II pediatric patients, aged 1 to 16 years, undergoing outpatient strabismus surgery. Interventions Patients were assigned to one of four doses of droperidol (10, 20, 40, or 80 μg · kg -1) (Groups 1, 2, 3, and 4, respectively). All patients received the same anesthetic management, with droperidol administered intravenously immediately after induction of anesthesia. Measurements and main results Postoperatively, patients were evaluated for emetic symptoms (nausea, retching, and/or vomiting) and side effects (postoperative sedation or extrapyramidal symptoms). There was a dose-dependent reduction of emetic symptoms seen with increasing droperidol dose. Predischarge emetic symptoms were 50%, 15%, 15%, and 5% in Groups 1, 2, 3, and 4, respectively ( p < 0.009). Peak emetic symptoms were observed after discharge: 75%, 40%, 35%, and 15% in Groups 1, 2, 3, and 4, respectively ( p < 0.003). Convalescence times, including awakening, extubation, recovery, and hospitalization, were unaffected by increasing droperidol dose. Sedation was similar in all groups and no patient exhibited any side effects. However, when patients exhibited emetic symptoms, discharge time increased from 207 ± 57 minutes to 283 ± 128 minutes ( p < 0.001). Conclusions Prophylactic administration of droperidol 80 μg · kg -1 is most effective in reducing postoperative emetic symptoms without increasing time to discharge. In those patients with emetic symptoms who also received prophylactic droperidol, time to discharge was significantly delayed.