The study has been planned to compare the antiemetic efficacy of ondansetron and dexamethasone combination with that of the single use of ondansetron to decrease the incidence of PONV. The study was planned in the Department of Surgery in Lord Buddha Koshi Medical College and Hospital, Saharsa, From September 2014 to September 2015. The age group of the patients is ranges from 20 to 60 years. Total 100 patients were evaluated for the study. GROUP A: Patients received inj. droperidol 20 mg per kg or inj. And GROUP B: Patients received inj. metoclopramide 0.2 mg per kg. We had conclude that combination of dexamethasone with ondansetron is quite effective in controlling PONV in patients. It also reduces incidence of nausea in first 24 hours post operatively and also frequency of giving rescue antiemetic is decreased.