The objective of the study was to evaluate the efficacy and safety of 800 microg misoprostol (Cytotec) every 8 h for 24 h for pharmacological abortion; the treatment was repeated if abortion did not occur in the first 24-h interval. The first misoprostol doses were always self-administered into the vagina; the second and third doses could be administered orally or vaginally depending on the amount of bleeding. Four-hundred and fifty-two women with gestations between 36 and 63 days were recruited into the study. The main outcomes assessed were: successful abortion (complete abortion without surgery), side effects, mean drop in hemoglobin, vaginal bleeding and mean time of return of menstruation. Complete abortion occurred in 409/452 (90.5%; 95% confidence interval [CI] 87%, 93%) patients. Medication to relieve symptoms was administered to all women before the first misoprostol dose. Vaginal bleeding lasted 15.9 +/- 4.4 days. The mean drop in hemoglobin, measured 14 days after abortion, was statistically significant (p = 0.0001) but without clinical relevance. According to the results obtained, 800 microg of misoprostol administered every 8 h for 24 h could be a valid method for abortion for up to 9 weeks of gestation.