Reports on the school climate for gay and lesbian students in the United States suggest that negative attitudes toward gay and lesbian individuals are quite common in adolescence. Very little research, however, has investigated adolescents' sexual prejudice from a developmental perspective. In this study, 10th- (N = 119) and 12th- (N = 145) grade adolescents and college-aged young adults (N=86) completed a questionnaire assessing their beliefs and attitudes about homosexuality, their comfort with gay and lesbian students, and their judgments and reasoning regarding the treatment of gay or lesbian peers in school. Results indicate that middle adolescents (14-16) are more likely than older adolescents (16-18) and young adults (19-26) to exhibit sexual prejudice related to social interaction with gay and lesbian peers. Interestingly, however, age-related differences in beliefs about whether homosexuality was right or wrong were not found. These findings provide evidence for age-related differences in some aspects of sexual prejudice but not others and underscore the importance of using multiple measures in assessing the development of this type of prejudice.