PURPOSE: The purpose of this commentary is to explain how social constructions of black sexuality are relevant to research targeting black sexual behavior and the ostensibly new and race-specific phenomenon known as "the Down Low" (the DL). The term "the DL" is widely used to refer to black men publicly presenting as heterosexual while secretly having sex with other men and presumably spreading human immunodeficiency virus and acquired immune deficiency syndrome (HIV/AIDS) to unsuspecting women. METHODS: We briefly review lay and public health literature from 1998 to 2004 about the DL, describe existing social constructions of black sexuality, discuss two implications for epidemiologic research, and offer recommendations to guide future research. RESULTS: The lifestyle referenced by the term the DL is neither new nor limited to blacks, and sufficient data linking it to HIV/AIDS disparities currently are lacking. Common perceptions about the DL reflect social constructions of black sexuality as generally excessive, deviant, diseased, and predatory. Research targeting black sexual behavior that ignores these constructions may unwittingly reinforce them. CONCLUSIONS: Unaddressed social constructions of black sexuality have implications for epidemiologic research targeting black sexual behavior. Explicit examination of these concerns is necessary to eliminate fundamental causes of health disparities.