The antiprogesterone mifepristone (RU 486) was synthesized in 1980 by Roussel-Uclaf (Paris). Since 1982 several studies have examined the ability of the drug to interrupt early pregnancies. 600 mg of mifepristone given by mouth to pregnant women with an amenorrhea of less than 50 days will lead to vaginal bleeding in more than 97% of the cases. The bleeding will be followed by moderate (menstruation-like) pain, and complete abortion will occur in 75% of the cases. A success rate of 75% is not sufficient for clinical use. The treatment should therefore consist of a combination of mifepristone and prostaglandin. The prostaglandin can be administered either by i.m. injections or as a vaginal suppository given 38-48 hours after the patient has received 600 mg of mifepristone by mouth. Such a combination of mifepristone and prostaglandin results in a complete abortion rate of more than 95%. Pelvic inflammatory disease (P.I.D.) after these abortions is extremely rare (below 0.5%), and other serious side effects are also uncommon. We find that mifepristone in combination with prostaglandin should be offered to Danish women seeking abortion as an alternative to the traditional method of vacuum aspiration.