AbstractThis study was designed to look at the role sexual arousal and behavior play in confirming or resolving gender identity confusion, and at how female‐to‐male transsexuals (FTs) and lesbians (Ls) differ in this area. Detailed interview data on sexual behavior from a clinical sample of 15 FTs compared to a matched research sample of 15 Ls are presented. The mean age for the FTs group was 21 years, 10 months and 23 years, 8 months for the Ls group. The two groups were matched by age, educational background and parental socioeconomic status. The results indicated that the majority of women in both groups had had sexual experience with men as well as women. All clearly preferred women as partners, but the FTs fantasized being men in encounters with women, while the Ls were completely identified women. The Ls sample tended to go through a heterosexual phase before they had their first relationship with another woman, which was typically not until approximately age 20. However, the FTs tended to have their first sexual relationship with a woman in early or middle adolescence. The two groups also differed in various aspects of sexual arousal and behavior, with Ls reporting a higher frequency of orgasms and being more at ease in engaging in intense and satisfactory sexual relations.The primary value of this study has to be seen as hypothesis rendering. The conclusions are tentative because of the limited sample size. The data add to our knowledge on aspects of female sexuality in general, and the reported differences between the two groups will assist in formulating a differential diagnosis between FTs and Ls in clinical practice.