At Maputo Central Hospital in Mozambique, intravaginal misoprostol, a PGE2 methyl-analogue, was used by 169 women whose request for interruption of pregnancy had been approved. The drug was used by women who had completed between 12 and 23 weeks of gestation. The initial dose was 800 micrograms, repeated 24 hours later if abortion had not occurred or was not in progress. The treatment was considered a failure when abortion was not advanced by 48 hours after the initial dose, and curettage was performed in all but one of such cases. During the course of the study, the dosage was successively reduced to 600, 400, and 200 micrograms. Abortion was successfully induced in 154 women (91.1 percent); there were 10 failures (5.9 percent), and five women (3.0 percent) dropped out of the study. The mean time from initial dose to abortion was 14.3 hours. No significant association of success rate and time from dosage to expulsion was found with age, parity, previous abortion, or gestational age. Preventive vacuum aspiration of the uterine cavity was carried out on all subjects.