PIP: In order to study the appropriate dosage in using RU 486 for induced abortion, 80 women of or = 49 days of pregnancy were randomly assigned to 3 groups. 20 women in Group I took 175 mg of RU486 in 3 1/2 days and were given 1 mg injection of prostaglandin (PG) on the 4th day. 20 women in Group II took the same amount of RU486 as group I and were given 0.5 mg of PG injection on the 4th day. 40 women in Group III took 100 mg of RU486 in 2 days and were given 0.5 mg of PG on the 3rd day. The duration of induced abortion and bleeding and the side effects were observed. The outcome of induced abortion was classified as complete abortion, incomplete abortion, and failure. No failures occurred. About 95% of the women in each group had a complete abortion, and the differences among the 3 groups were not statistically significant. Those who had an incomplete abortion received a medical abortion. A small number of women experienced the side effects of dizziness, nausea, vomiting, and diarrhea. Compared with studies with a similar proportion of complete abortion, the dosage of RU486 in this study is 2-4 times smaller, and the dosage of PG is also reduced by 5 to 14 times that used in earlier studies. Signs of incomplete abortion should be closely observed, and action should be taken to avoid excessive bleeding or infection. Drug-induced abortion is gradually gaining acceptance; nevertheless, appropriate medical attention is necessary to guard against complications.