Sexual orientation can be accurately identified from photos of faces, but previous work has focused exclusively on straight versus gay and lesbian individuals. Across three studies, the current work investigated the facial perception of bisexual men and women, a less socially salient category. Although participants could identify straight and gay men at above-chance levels in a trichotomous categorization task, bisexual men were categorized only at chance (Study 1). Participants perceived bisexual men to be significantly different from straight men, but not gay men (Study 2). Similarly, whereas bisexual and lesbian women were not rated differently, both groups were distinguishable from straight female targets (Study 3). These findings suggest a straight-non straight dichotomy in the categorization of sexual orientation.