BACKGROUND To investigate individual, interpersonal, and social-structural factors associated with involuntary sex exchange among female sex workers (FSWs) along the Mexico-U.S. border. METHODS In 2010 to 2011, 214 FSWs from Tijuana (n = 106) and Ciudad Juarez (n = 108) aged ≥ 18 years who reported lifetime use of heroin, cocaine, crack, or methamphetamine, having a stable partner, and having sold/traded sex in the past month completed quantitative surveys and HIV/sexually transmitted infection testing. Logistic regression was used to identify correlates of involuntary sex exchange among FSWs. RESULTS Of 214 FSWs, 31 (14.5%) reported involuntary sex exchange These women were younger at sex industry entry [adjusted odds ratio (AOR): 0.84/1-year increase, 95% confidence interval (CI): 0.72 to 0.97] and were significantly more likely to service clients whom they perceived to be HIV/sexually transmitted infection-infected (AOR: 12.41, 95% CI: 3.15 to 48.91). In addition, they were more likely to have clients who used drugs (AOR: 7.88, 95% CI: 1.52 to 41.00), report poor working conditions (AOR: 3.27, 95% CI: 1.03 to 10.31), and report a history of rape (AOR: 4.46, 95% CI: 1.43 to 13.91). CONCLUSIONS Involuntary sex exchange is disproportionate among FSWs who begin to exchange sex at a younger age, and these women experience elevated risk of violence and HIV/STIs related to their clients' behaviors and their working conditions. These data suggest the critical need for evidence-based approaches to preventing sexual exploitation of women and girls and to reducing harm among current sex workers. Multilevel interventions for all females who exchange sex and their clients that target interpersonal and social-structural risks (eg, measures to improve safety and reduce exploitation within the workplace) are needed.