Sex risk behaviors and substance use are intertwined. Many men continue to engage in high-risk sexual behaviors even when enrolled in substance use disorder (SUD) treatment. We hypothesized that changes in sex risk behaviors would coincide with changes in drug/alcohol use severity among men in SUD treatment. During an HIV risk-reduction trial, men in methadone maintenance and outpatient drug-free treatment (N = 359) completed assessments at baseline and six months after. We assessed changes in sex risk and substance use severity, using the Addiction Severity Index-Lite (ASI-Lite), controlling for treatment condition. In multinomial logistic regressions, decreased alcohol severity was significantly associated with decreases in reported sex partners, and increased alcohol severity was significantly associated with increases in reported sex partners. Increasing drug use severity was significantly associated with maintaining and initiating sex with a high-risk partner, while decreasing alcohol use severity was significantly associated with discontinuing sex under the influence. However, changes in drug/alcohol use severity were not associated with changes in unprotected sex. Substance use reductions may decrease HIV risk behaviors among male substance users. Our findings highlight the importance of integrating interventions in SUD treatment settings that address the intersection of sex risk behaviors and substance use.
