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