This study was undertaken to find out the efficacy of oral premedication with ondansetron to prevent post-operative nausea and vomiting in diagnostic gynaecological laparoscopy assisted surgery and to compare it with metoclopramide. We studied fifty patients of ASA physical status I & II, aged between 18-30 years and body weight between 50-60 kgs. The patients were randomized in equal numbers into two groups; Group A patients were received Tab Metoclopramide 10 mg orally an hour before operation and regarded as control and Group B patients were received Tab Ondansetron (0.15 mg/kg) or total 8 mg orally an hour before operation as case. They received a standard general anesthetic. Post-operative analgesia was provided with per rectal diclofenac sodium (50mg). In the recovery room occurrences of nausea and vomiting was assessed for 24 hours. The incidence of nausea was 80% in Group-A, 24% in Group-B (p<0.001) and vomiting was 64% in Group-A, 16% in Group-B (p<0.001). The difference among the groups was statistically significant. Key words: Laparoscopy assisted gynaecological surgery, PONV, oral ondansetron, metoclopramide. Journal of BSA, 2008; 21(2): 67-71