The purpose of the research was to evaluate clinical course and efficiency of the method of termination of pregnancy in the first end second trimesters by means of antiprogesterone. 384 women aged 15 to 45 in the first end second trimesters of pregnancy were investigated. 300 women had an early pregnancy (range=2-7 weeks) requesting abortion. All these women first took 600 mg antiprogesterone pencroftone ("Pencroft-Fharma", Russia) and 48 hours later - 400 mkg prostaglandin misoprostol. 84 patients with gestation period ranged from 14 to 22 weeks. Their contractility utterly was caused with 400 mg pencroftone and 48 hours later with 400 mkg prostaglandin misopristol. In the first trimester completed abortion was observed in 96,7%, incomplete abortion in 1,7%; missed abortion in 2,3% cases, continuing pregnancy in 1 case. In the second trimester in the case of therapy with pencroftone and prostaglandin E1 misoprostol the clinical effect was observed in 96,4% cases. Antiprogesterone pencroftone is an effective for medical abortion during I-II trimesters of pregnancy. It is characterized by minimal risk of complications in the course and the post abortion period.