Background and aims: Posttraumatic stress disorder (PTSD) is highly prevalent among forced migrant populations and is often accompanied by comorbid mental and physical health problems, and low levels of physical activity (PA). This study evaluated a multi-component, trauma-informed PA intervention for refugees on symptoms of PTSD, depression, anxiety, and subjective wellbeing. Additional process outcomes included levels of PA, sedentary time, and intervention adherence. Methods: A randomized controlled trial with two arms: intervention group (IG) receiving a 10-week traumainformed PA intervention and a waitlist control group (CG). Assessments occurred pre- and post-intervention and at 6-month follow-up. PTSD symptoms (primary outcome) were assessed using the PTSD Checklist for DSM-5 (PCL-5). Intervention effects were evaluated using mixed-effects linear regression models. Results: The sample comprised 183 participants (age 22-67, 41 % women), with 92 in the IG and 91 in the CG. The IG showed significant reductions in PTSD symptoms from baseline to post-intervention and 6-month followup (p < .001), with estimated PCL-5 scores of 52.3, 40.9, and 37.6. The between-group difference in PTSD symptoms at post-intervention (MD =10.0, 95 % CI [6.2, 13.7], p < .001) reflected a large effect size (d = 0.81), with similarly large effects for depression and anxiety (d = 0.83) and subjective wellbeing (d = 0.98). IG participants shifted from below to above the cutoff for sufficient PA, and all improvements persisted or further increased at 6-month follow-up. Conclusion: The findings provide important evidence supporting PA in the treatment of PTSD and associated comorbidities among trauma-affected refugees.