Lesbians, like other marginalized groups of women, under-utilize health care services. Lesbians also present later for health care than heterosexual women. Lack of awareness of the health issues of lesbians by some health care professionals has produced lesbians' abstention from health services. After defining lesbianism, I discuss how homophobia is a public health problem. Health issues of lesbians and practical recommendations for providing optimal gynecologic and obstetric care are presented on the subjects of adolescence, sexual identity, behavior and practice, sexually transmitted diseases, human immunodeficiency virus, Papanicolaou smears, cancer risk, fertility, and parenting issues. The discussion addresses how women's health research can be shaped to enhance knowledge about lesbian health. By changing physicians' attitudes and knowledge about lesbians, better communication and more sensitive interactions should result, improving the health care of lesbian patients.