Although prevalent among people living with human immunodeficiency virus (HIV) (PLWH) and people who use unregulated drugs (PWUD), pain and its possible links to substance use patterns and engagement in HIV treatment remains poorly characterized. We sought to evaluate the prevalence and correlates of pain among a cohort of PLWH who use un-regulated drugs. Between December 2011 and November 2018, 709 participants were recruited, and data were analyzed using generalized linear mixed-effects (GLMM). At baseline, 374 (53 percent) individuals reported moderate-to-extreme pain in the previous 6 months. In a multivariable model, pain was significantly associated with nonmedical prescrip-tion-opioid use (adjusted odds ratio (AOR) = 1.63, 95 percent confidence interval (CI): 1.30-2.05), nonfatal overdose (AOR = 1.46, 95 percent CI: 1.11-1.93), self-managing pain (AOR = 2.25, 95 percent CI: 1.94-2.61), requesting pain medication in the previous 6 months (AOR = 2.01, 95 percent CI: 1.69-2.38), and ever being diagnosed with a mental illness (AOR = 1.47, 95 percent CI: 1.11-1.94). Establishing accessible pain management interventions that address the complex intersection of pain, drug use, and HIV-infection has potential to improve quality of life outcomes among this population.