PONV occurs frequently after day case gynaecological surgery both 5-HT3 antagonists and dexamethasone are superior to placebo in the prophylaxis of PONV in his setting.Our study has compared. The efficacy of ondansetron plus dexamethasone with each anti-emetic alone for the prevention of PONV in patients undergoing day case gynaecological surgery. Present study was undertaken on 120 patients in the age group of to 65 years with ASA grades I & II undergoing gynaecologic laparoscopic intervention under general anaesthesia. Group 1 received Inj. Ondansetron 4mg with Inj. Dexamethasone 8mg as single dose I V bolus 5 minutes before induction of anaesthesia.Group 2 received Inj. Ondansetron 4mg as single dose I V bolus 5 minutes before induction of anaesthesia.Group 3 received Inj. Dexamethasone 8mg as single dose I V bolus 5 minutes before induction of anaesthesia.A standard anaesthetic protocol was used in all the patients. 5 min prior, the patients received the anti-emetic as per their groups Induction of general anaesthesia was done with Inj. Propofol 2-3 mg / kg IV. Intubating conditions were achieved with Inj. Suxamethonium 2 mg / kg I V. Trachea was intubated with appropriate sized cuffed PVC endotracheal tube. General anaesthesia was maintained with O2 + N2O::40:60.,skeletal l muscle relaxation was maintained with of Inj. Atracurium 0.5mg / kg as loading dose and 0.05mg/kg as supplemental doses. The duration of anaesthesia, surgery, pneumoperitoneum was noted.Nasogastric tube was introduced after induction & suction of gastric contents was done before recovery & was removed after extubation.The patients were evaluated at regular intervals of time in the post operative period for complaints of nausea, vomiting.As per our observations, the incidence of PONV in 0-4 hours post operative period was statistically significant. The observations were inconclusive beyond the 4 hour period in combination group as well as either drug group. Combination of Inj. Ondansetron 4mg with Inj. Dexamethasone 8mg proved to be more efficacious over either drug alone.