We performed a personal survey in 2218 Spanish women aged from 15 to 49 years to establish the contraceptive methods used by this population and to determine the number of Spanish women of childbearing age exposed to unwanted pregnancy. Stratified random sampling was performed to select the women to be interviewed; this sampling design ensured adequate representation of the sample in Spain. At the time of the survey, 69.1% of the women were using some contraceptive method, but 5% of them used poorly effective contraceptive methods, and their exposure to the risk of an unwanted pregnancy was therefore high. Moreover, among the 30.9% not using any contraceptive method, 21.1% were at risk because they were having sexual intercourse, did not want to become pregnant and did not use a contraceptive method. A little over one million Spanish women are exposed to the risk of having an unwanted pregnancy. Compiling the data on this significant problem is the first step in designing appropriate solutions.