Background: There is a high incidence of postoperative nausea and vomiting (PONV) in patients undergoing dilatation and curettage under general anesthesia using sevoflurane. We evaluated whether the combination of dexamethasone and on dansetron could prevent the PONV in patients undergoing dilatation and curettage uuder sevoflurane anesthesia. Methods: In a prospective randomized controlled, double blind study, 76 patients (ASA I-II) scheduled to receive dilatation and curettage were randomly divided into two group. During preoperative period, patients in the treated group received dexamethasone 8 mg and ondansetron 4 mg intravenously while patients in the control group received placebo. A standardized general anesthesia using under mask technique was used with sevoflurane in N 2 O : O 2 . All episodes of PONV and visual analoque pain scores were evaluated during the recovery period, 3-6 hr, 6-12 hr and 12-24 hr of postoperative periods. Results: There was no difference in the episode of PONV during 24 hr of postoperative period (22.0% vs. 34.3%) p = 0.347. Conclusion: By using the combination of dexamethasone and ondansetron, the incidence of PONV is not statistically significant different from using placebo in patients undergoing curettage under sevoflurane anesthesia