Life-history data from a nationally representative survey of Australian women were used to examine discontinuation of contraceptive methods because of accidental pregnancy, side effects or dissatisfaction. The pill was the most successfully used method, with a first-year discontinuation rate of 10% for all three reasons. Side effects dominated the reasons for the premature discontinuation of both the pill and the IUD, while the reasons for discontinuing the condom stemmed equally from pregnancy and dissatisfaction with the method. Discontinuation of the diaphragm resulted largely from accidental pregnancy. Hazards models were used to identify the correlates of discontinuation of each method. Predictors of premature discontinuation reflect the availability of methods, physiological reactions to them and the social characteristics of their users. Discontinuation of the pill because of side effects or dissatisfaction was more likely among poorly educated women, non-Protestants and recent users, and less likely among teenagers. Discontinuation of the IUD was related entirely to physiological factors: Nulliparous women and users of unmedicated devices were at a greater risk than other women of accidental pregnancy, and nulliparous women were at greater risk of discontinuation associated with side effects. Nulliparous women were also more likely to discontinue the condom because of pregnancy, as were non-Protestants and the Australian-born.