The authors examined whether gay men and lesbians are evaluated more negatively than individuals of unspecified sexual orientation when attributional ambiguity surrounds evaluations and whether they are evaluated similarly to unspecified others when no attributional ambiguity is present. One male and one female lecturer delivered either a strong or a weak lecture to students who either (a) believed that the lecturer was a gay man or a lesbian or (b) did not receive sexual orientation information. Contrary to predictions, the quality of the lecture did not influence the ratings of known gay male and lesbian lecturers, although lecture quality strongly influenced ratings of lecturers whose sexual orientation was unspecified. After strong lectures, participants rated known gay male and lesbian lecturers more negatively than they did lecturers whose sexual orientation was unspecified. After weak lectures, participants rated known gay male and lesbian lecturers more positively than they did the others. The authors discussed the possibility that students might moderate their ratings to avoid discriminating against gay and lesbian lecturers.