How do people's self-reported (i.e., explicit) attitudes, automatically activated (i.e., implicit) attitudes, and gender interact to predict discriminatory behaviour against a gay man? In the context of a mock employment study, participants interacted with a confederate whose appearance and responses were designed to provide cues that he was gay. Results revealed that higher levels of implicit prejudice, but not explicit prejudice, predicted subtle discriminatory behaviour (i.e., speech hesitations) and deliberative evaluations of the confederate. In addition, explicit prejudice, implicit prejudice, and gender interacted to predict both subtle and blatant discriminatory behaviour against the confederate. Notably, among men who self-reported lower levels of prejudice against gay men, those with greater automatically activated prejudice were more likely to negatively evaluate the confederate. These intriguing results are discussed with respect to their theoretical implications for conceptualizing explicit and implicit prejudice and in terms of their practical implications concerning discrimination against gay men.