Nine hundred and fourteen heterosexual persons who requested care at STD clinics in South Carolina responded to self-administered questions on STD history, socio-demographic characteristics, number of sexual partners, and sexual partner choice. These data and the current STD diagnosis were analysed using multivariate techniques. Sexual behaviors of men and women were different. Men reported greater number of partners and less discriminating sex partner recruitment patterns. Age, rural/urban residence, race, and number of sex partners were independent predictors of gonorrhea infection among men. Among women, age, rural/urban residence, and not knowing the most recent sex partner very well emerged as independent predictors of infection.