Prevention and treatment of postoperative nausea and vomiting with ephedrine, droperidol and metoclopramide have been reported to be effective. To further investigate their efficacy, 100 pediatric patients scheduled to undergo inguinal hernioplasty on ambulatory basis were divided into five groups, namely, group 1: normal saline (iv) control; group 2: ephedrine 0.5 mg/kg, (im); group 3: droperidol 50 micrograms/kg. (iv); group 4: ephedrine 1 mg/kg. (im); group 5: metoclopramide 0.15 mg/kg. (iv). At the end of surgery, each patient received the drug treatment according to the specified group to which he was randomly assigned. The occurrence of postoperative nausea and vomiting was recorded in the recovery room and inquired at home by telephone within 24 h following surgery by a blinded observer. The authors found that there were no significant differences between the control group and ephedrine groups with whichever dose that was used in the prevention of postoperative nausea and vomiting. Droperidol and metoclopramide were effective in dealing with problem in comparison with control group (p less than 0.05). However, metoclopramide was more suitable than droperidol for pediatric outpatient based on duration of somnolence, return of orientation, and time of discharge.