Although existence and functioning of a sexual relationship is of outstanding importance for the abortion decision as well as for the postabortive emotional adjustment, until now there are only some case studies focussing on the postabortive reaction of the sexual relationship. Results of a representative and controlled follow-up-study investigating the effects of legal abortion on the relationship with a partner are reported here. 117 women, a representative sample of all 263 women having a socially indicated legal abortion during the first 3 months of 1982 in Kiel, were interviewed some days before and 1 year after the abortion. The effects of abortion on the sexual relationship are described in comparison with a control group with similar preabortive characteristics of partnership using hormonal or intrauterine contraceptive devices. Rate and circumstances of separation, especially the role of abortion for the separation, as well as the quality of the remaining relationships have been analysed. We could find preabortive variables easily accessible for the counselor, predicting the development of the sexual relationship regarding quality and stability in the year after abortion.