In the present study, a modified standardized sexual function questionnaire, along with a test of knowledge about and attitude toward sexuality, was administered to 300 healthy women, ages 16 through 53, who sought services at family planing centers in Tehran, Iran. All participants were married. The greatest percentages had two children (35%) and were housewives (69%). Some 72% were well educated, and 1% were illiterate; 74% of the women had moderate knowledge about sexuality, and 53% had a conservative attitude toward sexuality. The study revealed the prevalence of inhibited desire (15%), inhibited orgasm (26%), lack of lubrication (15%), vaginismus (8%), and dyspareunia (10%); 38% of the women had at least one sexual dysfunction. The most common sexual difficulties reported were "too little foreplay before intercourse" and "partner chooses inconvenient time" (8% each). Despite these difficulties, 51% of the sample reported that their overall sexual relationship was satisfactory. Knowledge about sexuality was significantly correlated with orgasm experience, higher knowledge being associated with more orgasm experience. There were significant correlations between attitude toward sexuality and sexual function (orgasm, desire, lubrication); a conservative attitude was associated with more sexual dysfunction. Spousal sexual dysfunction had a significant negative correlation with sexual function in the woman.