Men who have sex with men (MSM) and women who have sex with women (WSW) are purportedly neutral terms commonly used in public health discourse. However, they are problematic because they obscure social dimensions of sexuality; undermine the self-labeling of lesbian, gay, and bisexual people; and do not sufficiently describe variations in sexual behavior.MSM and WSW often imply a lack of lesbian or gay identity and an absence of community, networks, and relationships in which same-gender pairings mean more than merely sexual behavior. Overuse of the terms MSM and WSW adds to a history of scientific labeling of sexual minorities that reflects, and inadvertently advances, heterosexist notions. Public health professionals should adopt more nuanced and culturally relevant language in discussing members of sexual-minority groups.