Objective: Precision medicine is an area with great potential for mental health, but has made limited gains prognostically in predicting effective treatments. For refugees exposed to violence, culture may be a crucial factor in predicting treatment outcomes. Method: For this study, 290 participants from three regions (Afghanistan, the Great Lakes region of Africa, and Iraq and Syria) participated in a randomized controlled trial of an advocacy-based intervention. Emotional distress symptoms were measured prior to intervention, midintervention (3 months), postintervention (6 months), and follow-up (6 months after the end of intervention). Number of traumatic events, resource access, social support, and English proficiency were tested for potential predictive effects on intervention outcome. Results: Multilevel generalized linear models revealed that Afghans' (B = −0.259, SE = 0.108, p = .013), and Great Lakes Africans' (B = −0.116, SE = 0.057, p = .042) emotional distress symptoms improved as a function of the intervention, while Iraqis and Syrians showed no intervention effects. For Afghans, English proficiency (B = −0.453, SE = 0.157, p < .01) and social support (B = −0.179, SE = 0.086, p = .037) were most strongly correlated to emotional distress, while for Africans, resource access (B = −0.483, SE = 0.082, p < .001) and social support (B = −0.100, SE = 0.048, p = .040) were the strongest predictors of emotional distress. Conclusions: Response to advocacy-based interventions and active ingredients may be influenced by culture; findings have