Although a significant proportion of the population is gay or lesbian, physicians receive little formal training about homosexuality, and the unique health care needs of these patients are often ignored. Gay men and women may have higher rates of depression, suicide, alcoholism, certain cancers, and cardiovascular disease than their heterosexual counterparts. In addition, they are at risk of being victims of violence because of their sexual orientation. Due to fear of stigmatization by the medical community, the most significant health risk for lesbians, gays, and bisexuals may be that they avoid routine health care. Gay youth are particularly vulnerable to internal and external pressures, resulting in higher rates of substance abuse, suicide, and homelessness. Older gay men and women, who generally view themselves positively, may be troubled by declining health and loneliness. Physicians can improve the health care of gay and bisexual men and women and their families by maintaining a non-homophobic attitude toward these patients, distinguishing sexual behavior from sexual identity, communicating with gender-neutral terms, and maintaining awareness of how their own attitudes affect clinical judgment. Medical educators should avoid making assumptions about the sexuality of their residents and students. Institutions need to realize that the presence of supportive heterosexual and openly gay faculty will help create an environment that fosters learning for all students. Scant research exists about the best ways to teach about the special challenges gay men and lesbians face. However, the majority of surveyed medical students prefer that issues regarding gays and lesbians be integrated throughout the entire medical school curriculum.