This study tested the hypothesis that all gender-dysphoric males who are not sexually aroused by men (homosexual) are instead sexually aroused by the thought or image of themselves as women (autogynephilic). Subjects were 212 adult male-to-female transsexuals. These were divided into four groups: one homosexual and three nonhomosexual. The three nonhomosexual groups were heterosexual, bisexual, and analloerotic (unattracted to male or female partners, but not necessarily devoid of all erotic behavior). A Core Autogynephilia Scale was developed to assess a subject's propensity to be sexually aroused by the fantasy of being a woman. The four transsexual groups were compared on this measure (and on several others), using Newman-Keuls multiple-range tests at p <. 05. As predicted, all three nonhomosexual groups were more likely than the homosexual group to report sexual stimulation by cross-gender fantasy. This finding supports the hypothesis that the major types of nonhomosexual gender dysphoria constitute variant forms of one underlying disorder, which may be characterized as autogynephilic gender dysphoria.