Background and objective : Acetaminophen is a well known analgesic for mild to moderate pain. After ambulatory uterine curettage pain is expected to be mild or moderate. However, systemic opioid is normally given to relieve pain which may delay recovery. Oral acetaminophen premedication given before the procedure should be suitable to relieve post operative pain. Material and Methods : Randomized, double blinded, control study was conducted. Two hundred and three outpatients age 18-60 years ASA class I-II undergoing curettage procedure were randomly allocated into 3 groups. The patients in group A 1000 (n = 73) received oral acetaminophen 1000 mg of acetaminophen, group A 500 (n = 68) received 500 mg of acetaminophen, the placebo group (PA) (n = 62) only placebo, all were given 30 minutes before starting the procedure. Total intravenous anesthesia with propofol and fentanyl was provided for all patients. The pain intensity was evaluated using verbal rating scale (VRS; 0-10) at recovery time and 4, 8, 24 hours after premedication. Result : All three groups had mild pain intensity. There was no significant difference in pain intensity at recovery time and 8, 24 hours after premedication. However, pain intensity at 4 hours after premedication was significantly different since patients in group A1000 had a pain score lower than the placebo group (P = 0.02). Median (range) time required for the first dose of paracetamol was 420 (120-1470) minutes in group A1000, 450 (90-1170) minutes in group A500 and 270 (80-900) minutes in the placebo group (P=0.029) Conclusion : Acetaminophen in dosage of 500 and 1000 mg given as premedication is effective for post operative pain after uterine curettage procedure at 4 hour after premedication. In addition, a prolonged requirement of the first dose of paracetamol was found in paracetamol groups compared to the placebo group.