The purpose of the present study was to compare prapofol, newly introduced anesthetic agnet, & thiopental as to the characteristics of induction & recovery as well as the safety of both anents. Fifty patients who presented for termination of pregnancy were allocated at random to recieve either propofol 2 mg/kg IV or thiopental 4 mg/kg IV. In addition all patients recevied fentanyl, 1 ug/kg IV, one minute befor the induction. Repeated bolus doses of either propofol 20 mg or thiopental 50 mg were given, if the patient respond to surgical stimulation by moving. The result were as follows. 1) Both propofol and thiopental produced smooth and rapid induction, but caused significant respiratory depression. 2) There was more cardiovascular depression with propofol than with thiopental. 3) Postoperative recovery(time to ambulation) was faster with propofol than with thiopental (36.5+/-1.4 vs 72.9+/-5.1 min, p<0.001). 4) Propofol was associated with less side effects(Nausea, vomithing, and dizziness) than thiopental. These results suggest 1) that propofol has significant advantage over thiopental in outpatient surgery, where early ambulation and discharge is desirable, and 2) that both propofol and thiopental should be administered by expert anesthesiologist only when ventiatory assistant device with oxygen is immediately available.