BACKGROUND: Despite the widespread use of highly effective contraception in France, the incidence of abortion is high. A retrospective population-based cohort study was designed to analyse women's contraceptive history. METHOD: We compared the contraceptive use of 163 women, whose last pregnancy ended in abortion, 6 months before, at the time of, 1 month and 6 months after the event with that of 1787 women who had never had an abortion. RESULTS: A total of 46% of women who experienced an abortion used a highly effective form of contraception 6 months before the event (versus 76% among women who had never had an abortion, P < 0.001). This proportion dropped to 33% at the time of the abortion and increased to 71%, 1 month after. In addition, 50% of women who had an abortion had changed their contraceptive method in the 6 months before the event (compared with 16% in the 6 months before the interview in women who had not had an abortion, P < 0.001). Women with socially deprived backgrounds were less likely to use a highly effective contraception after an abortion. CONCLUSIONS: Abortion is a good opportunity for intervention, but especially so for socially disadvantaged women. It is essential to draw the attention of prescribers and women to the higher risk of contraceptive failure at the start of use of a method.