Background: Posttraumatic stress disorder (PTSD) affects approximately 0.1% of children who have been exposed to serious adversities. We therefore set out to identify effective interventions for treating childhood PTSD.Methods: We used systematic review methods to identify randomized controlled trials (RCTs) evaluating treatment interventions for children who had diagnosed with PTSD. After applying our rigorous inclusion criteria, we accepted five RCTs – evaluating three psychosocial interventions and one medication.Results: Prolonged Exposure for Adolescents and KIDNET, both based on cognitive-behavioural therapy (CBT), showed significant benefits for children, including reduction of PTSD diagnoses, symptoms, and overall functioning compared to controls. In contrast, D-cycloserine failed to show benefit for children compared to controls. In a head-to-head trial, Eye Movement Desensitization and Reprocessing (EMDR) and CBT both reduced PTSD diagnoses and symptoms, with EMDR outperforming CBT in reducing diagnoses by parent-report at one-year follow-up.Conclusions: Preventing childhood adversities is priority. But when a child develops PTSD, access to effective treatment is crucial. CBT was effective in reducing diagnoses and/or symptoms across four RCTs in our systematic review.