HIV is disproportionately impacting Black men who have sex with men and heterosexual women in the United States. Current speculation posits a “bisexual bridge” of HIV transmission connecting these two subpopulations of the Black community. Specifically, bisexually active Black men who identify as heterosexual but do not disclose their same-sex behavior, or “down low” (DL) men, have received the most attention and blame as the primary group fueling this epidemic. This essay explores the current knowledge and limitations of public health research on bisexually active Black men. Implications for future research initiatives are discussed.