This study aimed to examine psychometric properties of a Malay version of the Children's Depression Inventory (CDI) by using Item Response Theory, particularly the Rasch model, among secondary school adolescents. The Survey method was employed in this quantitative study by distributing the self-report Malay version of the CDI (MCDI) questionnaire to a total of 500 secondary school adolescents in two randomly chosen daily, government (public) schools. The criteria for selecting respondents was that they possessed a minimum competency in the Malay language, were aged 14 or 16 years and were enrolled in secondary schools situated in the selected geographic area. Respondents meeting these criteria were then randomly chosen for this study. This validation study revealed that MCDI items pointing toward one dimension based on item MNSQ, PTMEA values, Rasch residual based on principal component analysis, adhered to Rasch model's expectation, good item separation index (7.30) and very high reliability (0.98). Independent T-test result revealed that females and males differed in terms of the MCDI total score. Female respondents were more susceptible to depression as compared to their male counterparts. School form was not a significant predictor for depression as evidenced by insignificant T- test results.