Black individuals represent 13 % of the US population but 46 % of HIV positive persons and 40 % of incarcerated persons. The national EnhanceLink project evaluated characteristics of HIV-positive jail entrants at ten sites and explored associations between race and HIV disease state. Between 1/2008 and 10/2011, 1,270 study participants provided demographic and clinical data. Adjusted odds ratios (aORs) were calculated for advanced HIV disease (CD4 < 200 cells/mm3) and uncontrolled viremia (viral load > 400 copies/ml) for Black (n = 807) versus non-Black (n = 426) participants. Sixty-five percent of HIV-positive jail participants self-identified as Black. Among all participants, fewer than half had a high school diploma or GED, the median number of lifetime arrests was 15, and major mental illness and substance abuse were common. Black participants were more likely to be older than non-Black participants, and less likely to have health insurance (70 vs 83 %) or an HIV provider (73 vs 81 %) in the prior 30 days. Among all male study participants (n = 870), 20 % self-identified as homosexual or bisexual. Black male participants were more likely to be homosexual or bisexual (22 vs 16 %) and less likely to have a history of injection drug use (20 vs 50 %) than non-Black male participants. Advanced HIV disease was associated with self-identification as Black (aOR = 1.84, 95 % CI 1.16–2.93) and time since HIV diagnosis of more than two years (aOR = 3.55, 95 % CI 1.52–8.31); advanced disease was inversely associated with age of less than 38 years (aOR = 0.41, 95 % CI 0.24–0.70). Uncontrolled viremia was inversely associated with use of antiretroviral therapy (ART) in the prior 7 days (aOR = 0.25, 95 % CI 0.15–0.43) and insurance coverage in the prior 30 days (aOR = 0.46, 95 % CI 0.26–0.81). Conclusions: The racial disparities of HIV and incarceration among Black individuals in the US are underscored by the finding that 65 % of HIV-positive jail participants self-identified as Black in this ten-site study. Our study also found that 22 % of Black male participants self-identified as men who have sex with men (MSM). We believe these findings support jails as strategic venues to reach heterosexual, bisexual, and homosexual HIV-positive Black men who may have been overlooked in the community. Among HIV-positive jail entrants, Black individuals had more advanced HIV disease. Self-identification as Black was associated with a lower likelihood of having health insurance or an HIV provider prior to incarceration. HIV care and linkage interventions are needed within jails to better treat HIV and to address these racial disparities.