A dearth of research to date has explored HIV risk among Black men who report sex with transgender partners. In 2008, 197 Black men residing in Massachusetts were recruited via modified respondent-driven sampling and completed an interviewer-administered survey. Overall, 8% reported sex with a transgender partner in the past 12 months. Over half (56%) reported unprotected sex during their last encounter with transgender partners. Factors significantly associated with having a transgender sex partner: history of substance abuse, incarceration, PTSD symptoms, lower levels of perceived social support, not having been exposed to HIV prevention services in the past 12 months, and endorsement of mobile van services as a comfortable location to access health care. These formative data suggest that Black men who partner with transgender individuals may be at elevated risk for an array of poorer health-related outcomes, including HIV sexual risk, substance abuse, incarceration, psychosocial vulnerability, and lack of access to health care. Theory-driven interventions that consider the broader context affecting the embodiment of HIV risk are warranted for men who have sex with transgender partners.