BACKGROUND Laparoscopic surgeries are the second most common cause of postoperative nausea and vomiting (PONV), which would cause unexpected delay in hospital discharge. This study intends to compare the efficacy and safety of the combination of ondansetron and dexamethasone with ondansetron alone given as prophylaxis for PONV in adults undergoing elective laparoscopic surgery. METHODS One hundred adult patients undergoing elective laparoscopic surgeries were selected and were randomly divided into 2 groups of 50 each. Group I received 4 mg of ondansetron intravenously (i.v.), whereas Group II received ondansetron 4 mg and dexamethasone 4 mg i.v. just before induction of anesthesia. Postoperatively, the patients were assessed for episodes of nausea, vomiting, and need for rescue antiemetic at intervals of 0-2, 3, 6, 12, and 24 h. Postoperative pain scores and time for the first analgesic dose were also noted. RESULTS Results were analyzed statistically. Complete response defined as no nausea or emesis and no need for rescue antiemetic during first 24 h, was noted in 76% of patients who received ondansetron alone, while similar response was seen in 92% of patients in combination group. Rescue antiemetic requirement was less in combination group (8%) as compared with ondansetron group. CONCLUSIONS Combination of ondanserton and dexamethasone is more effective in preventing post operative nausea vomiting in patients undergoing laparoscopic surgery than ondansetron alone.