Background: Most PTSD screening tools for children and adolescents have been validated in Western contexts which is not necessarily generalizable to non-western cultures. Therefore, the objective of this cross-sectional study was to determine the psychometric properties of the Child Posttraumatic Stress Disorder Reaction Index (CPTS-RI) within a Malaysian population. Methods: Eighty-five adolescents aged 13- to 14-years-old completed the CPTS-RI, Harvard Trauma Questionnaire (HTQ) and Hopkins Symptom Checklist scale (HSCL). Results: Results showed a good internal consistency for the overall scale (α =.92), for the subscale -re-experience, avoidance and arousal subscales (α = .89, α = .73, α = .56 respectively) and for different gender groups and ethnicity. CPTS-RI demonstrated good construct and divergent validity, and showed good concurrent validity with the use of HTQ and HSCL as the criterion measure. Conclusion: Findings suggest that CPTS-RI is a valid and reliable instrument to assess PTSD symptoms among Malaysian adolescents.