Women who exchange sex for money or other goods, that is, female sex workers, are at increased risk of experiencing physical and sexual violence from both paying and intimate partners. Exposure to violence can be exacerbated by alcohol use and HIV/STI risk. The purpose of this study is to examine the efficacy of a HIV/STI risk reduction and enhanced HIV/STI risk reduction intervention at decreasing paying and intimate partner violence against Mongolian women who exchange sex and engage in harmful alcohol use. Women are recruited and randomized to either (a) four sessions of a relationship-based HIV/STI risk reduction intervention (n = 49), (b) the same HIV/STI risk reduction intervention plus two additional motivational interviewing sessions (n = 58), or (c) a four session control condition focused on wellness promotion (n = 59). All the respondents complete assessments at baseline (preintervention) as well as at immediate posttest, 3 and 6 months postintervention. A multilevel logistic model finds that women who participated in the HIV/STI risk reduction group (OR = 0.14, p less than 0.00), HIV/STI risk reduction and motivational interview group (OR = 0.46, p = 0.02), and wellness (OR = 0.20, p less than 0.00) group reduced their exposure to physical and sexual violence in the past 90 days. No significant differences in effects are observed between conditions. This study demonstrates the efficacy of a relationship-based HIV/STI risk reduction intervention, a relationship-based HIV/STI risk reduction intervention combined with motivational interviewing, and a wellness promotion intervention in reducing intimate and paying partner violence against women who exchange sex in Mongolia. The findings have significant implications for the impact of minimal intervention and the potential role of peer networks and social support in reducing women's experiences of violence in resource poor settings. (Contains 3 tables.)