HIV-related stigma has a major impact on quality of life and health among people living with HIV and AIDS (PLWHA). This study examines demographic, mental health, behavioral, contextual, and HIV care-related correlates of HIV stigma among 503 substance abusing PLWHA. Stigma was measured with the HIV Internalized Stigma Measure which has four subscales: stereotypes about HIV, self-acceptance, disclosure concerns, and social relationships. Severe substance dependence (55.3%) and depression (54.7%) were associated with higher HIV stigma across all domains. 49.9% of the sample reported antiretroviral (ARV) medication diversion (the unlawful sale and trading of ARV medications); diverters endorsed significantly higher stigma related to disclosure. 54.1% of the sample reported ≥95% ARV adherence; these individuals reported significantly lower stigma for self-acceptance, disclosure, and social relationships. Multivariate linear regression showed that depression and social support demonstrated significant main effects across stigma domains. Findings suggest that interventions to decrease HIV related stigma may be an important component of initiatives to increase engagement in HIV care.