AbstractAlthough treatment guidelines recommend interventions entailing caregiver involvement for children and adolescents following traumatic experiences, evidence on their effectiveness is inconsistent. The present systematic review and meta-analysis considered possible moderators of their effectiveness. Method. Eligible studies were (quasi-)randomized controlled trials and efficacy trials published in English or German with participants up to the age of 21 years presenting symptoms of mental disorders due to traumatic experiences. The effectiveness of interventions entailing any kind and extent of caregiver involvement had to be investigated by applying evaluated instruments. PubMed, PsycINFO, ERIC, COCHRANE and PSYNDEX were searched. Results. A total of 33 studies with 36 independent samples were retrieved. Child- and parent-reports on PTSD, depression, anxiety, ADHD, internalizing, externalizing symptoms and behavior problems were analyzed where available. The pooled effect size is significant and robust at post-treatment for child-reported PTSD, g = − 0.34 (95% CI = − 0.53; − 0.14), parent-reported PTSD, g = − 0.41 (95% CI = − 0.71; − 0.11), child-reported depression, g = − 0.29 (95% CI = − 0.46; − 0.11), child-reported anxiety, g = − 0.25 (95% CI = − 0.42; − 0.08), and parent-reported internalizing symptoms, g = − 0.27 (95% CI = − 0.47; − 0.07). Female sex and fulfilling diagnostic criteria appeared as potential moderators. The only significant effect size at follow-up is found for child-reported PTSD symptoms 12 months post-treatment, g = − 0.37 (95% CI = − 0.67; − 0.07). Conclusions. Interventions entailing caregiver involvement revealed greater symptom reductions than control conditions. Determinants of their effectiveness should be examined further.