BackgroundThe association between sexual and physical abuse history, mental illness, and HIV risk behaviors among persons starting treatment for substance use is not well-understood. MethodsThe study population included 216,877 US residents in the National Addictions Vigilance Intervention and Prevention Program (NAVIPPRO) from January 1, 2014–December 31, 2019. We used logistic regression models to estimate strength of pairwise association between mental illness, sexual or physical abuse histories and each of 3 HIV risk outcomes. ResultsCompared with no history of physical or sexual abuse, a history of sexual and physical abuse combined was associated with greater odds ratios for: (1) injection drug use among persons without a history of mental illness (odds ratio [OR] 2.4; 95% confidence interval [CI]: 2.3–2.6) than among persons with a history of mental illness (OR 2.0; 95% CI: 1.9–2.0); (2) prostitution conviction among persons without mental illness (OR 3.8; 95% CI: 2.8–5.1) than among persons with mental illness (OR 2.8; 95% CI: 2.4–3.4); and (3) and ≥2 sex partners within the past 30 days with a history of mental illness (OR 1.3; 95% CI: 1.2–1.4). ConclusionsThe findings imply that efforts to reduce HIV risk behaviors during and after substance use treatment can be improved by considering the patient's history of physical or sexual abuse and mental illness when providing care.