OBJECTIVES--To examine the sexual behaviour and the prevalence of sexually transmitted diseases (STD) among females attending an inner-city STD clinic before and after safer sex campaigns. SUBJECTS--In 1984 981 women and in 1988 684 women were interviewed immediately after the venerological examination. SETTING--Department of Dermato-Venereology, Bispebjerg Hospital, Copenhagen, Denmark. METHODS--In a face to face interview, details of symptoms, age at coitarche, number of sexual partners (lifetime and during the last year), obstetric history, and contraceptive methods were recorded. RESULTS--A substantially higher proportion of women used condoms in 1988 than in 1984. A dramatic decrease in the prevalence of gonorrhoea occurred (from 22% in 1984 to 6% in 1988, p < 0.01), whereas an increase in the number of patients with genital warts was observed (from 4% in 1984 to 10% in 1988, p < 0.05). The prevalence of chlamydia, genital herpes, and cervical dysplasia remained unchanged. No significant changes in the number of sexual partners, or the frequency of sexual intercourse or unplanned pregnancy could be detected from 1984 to 1988. CONCLUSIONS--The safer sex campaigns have only been partly successful, as a general reduction in all sexually transmitted diseases should be expected as a result of the increased use of condoms. Future campaigns should focus on the correct use of condoms, and encourage a lifestyle with stable sexual relationship.