Research over the last two decades reveals widespread anti-gay prejudice on many college campuses. The college campus might be described as a place dedicated to the free and respectful exchange of ideas. We might think of it as a community in which harassment, intimidation, and violence are not tolerated. Unfortunately, many studies of college climate demonstrate that this is not the case for lesbian, gay and bisexual students. How college faculty address--or fail to address--issues of sexual orientation in and out of classrooms has a significant impact on the learning environment for all students, but especially for those who identify as lesbian, gay or bisexual. By supporting academic inquiry into sexual-orientation topics and creating a welcoming campus environment for all students, faculty contribute not only to the academic success of students, but also to the development of a positive self-identity. Conversely, by engaging in, or being oblivious to, homophobic harassment or discriminatory behavior, we perpetuate negative stereotypes, validate the hatred perpetrated against lesbian, gay and bisexual (LGB) individuals, and interfere with learning. This paper discusses the following: findings in attitude research of heterosexuals' attitude towards lesbians and gay men, and society's view of this attitude; factors contributing to anti-gay prejudice; challenging intolerance; and what faculty can do to improve the climate for lesbian and gay students in classes and on campuses.