Abstract Despite the severe impact of childhood sexual abuse (CSA) on trauma-related disorders, preventive interventions are scarce, especially in (post-)conflict regions. We developed and evaluated a narrative family communication approach for sexually abused Burundian female children and adolescents (N = 102). The intervention cohort (n = 55) received psychoeducation, parental skill training, and preventive narrative exposure therapy. Intervention participants reported improved parental acceptance at 3- and 12-month follow-ups (3mFUP, 12mFUP), and showed greater improvement in overall mental health between initial assessment (IA) and 3mFUP (d rm = -0.70) and between IA and 12mFUP (d rm = -1.36) compared to non-treated controls (d rm = -0.33, d rm = -0.02, respectively). Moreover, PTSD symptoms were significantly less pronounced in the intervention cohort than in the control cohort at both follow-ups. Our findings suggest that the preventive narrative family intervention might effectively buffer against devastating mental health consequences, including emerging PTSD symptoms, in the aftermath of CSA. The study and its outcome measures were preregistered at Clinical Trials (https://clinicaltrials.gov/) with the registration number NCT05136105.