This prospective, placebo-controlled, double-blinded, and randomized study was undertaken to compare the efficacy of granisetron, droperidol, and combinations of granisetron with droperidol or dexamethasone on postoperative nausea and vomiting in patients undergoing general anesthesia for cesarean section. Patients (n = 150) who were scheduled,for cesarean section under general anesthesia were randomly assigned to one of the five groups: physiological saline 5 ml in Group A, granisetron 40 mu g/kg + dexarnethasone 8 mg in Group B. granisetron 40 mu g/kg + droperidol 1.25 mg in Group C, droperidol 1.25 mg in Group D, and granisetron 40 mu g/kg in Group E were administered intravenously after clamping of the fetal umbilical cord. Postoperative nausea and vomiting was observed for 0-24 h after the anesthesia. Cesarean sections were all per formed under general anesthesia. Postoperative nausea and vomiting was more common in placebo group (56.7%) than the others during the 0-24 h after the anesthesia (p < 0.05). All granisetron groups were more effective than placebo and droperidol groups during the postoperative 3-24 h (13 < 0.01). Although this trial lacks statistical power, granisetron alone and combinations with droperidol or dexamethasone were effective similarly. All treatment groups, except droperidol during the postoperative 3-24 h, were effective for prevention of postoperative nausea and vomiting during tire postoperative 0-24 h. (c) 2005 Pious Science. All rights reserved.