A questionnaire asking about satisfaction and problems in the sex lives of respondents and their partners was sent to 4,000 adults registered with general practices in England. A quarter of respondents said that they were dissatisfied with their sex lives, men more so than women, particularly with the frequency of intercourse. Respondents were more likely to be dissatisfied with their sex life if they perceived their partner to have a sexual problem. Respondents who were dissatisfied were more likely to report that their partner was dissatisfied with their sex life. The benefits of treating sexual problems have wide implications for both partners in a relationship.