The relationship between gender dysphoria and autogynephilia (erotic arousal in men associated with the thought or image of themselves as women) was investigated. Subjects were 238 nonhomosexual male outpatients divided into three groups: 94 reporting they were most aroused sexually by images of themselves as nude women, 67 most aroused by images of themselves as women in underwear, and 77 most aroused by images of themselves as fully clothed women. These were compared on questionnaire measures of gender dysphoria and other psychosexual variables. The Nude group was significantly more gender dysphoric than the Clothed group, which, in turn, was significantly more gender dysphoric than the Underwear group. These results support the hypothesis that those nonhomosexual men most aroused sexually by the thought of having a woman's body are also those most interested in acquiring a woman's body through some permanent, physical transformation. A secondary finding was that the Nude group was the same age as the Underwear group and significantly younger than the Clothed group. This outcome makes it unlikely that erotic fantasies of having a woman's body are the end result of some progression that necessarily begins with erotic fantasies of wearing women's clothes.