Objectives:This study aims to develop a Personal digital assistant(PDA) version of the Korean Composite International Diagnostic Interview(K-CIDI) about major depressive disorder, alcohol and nicotine use disorder for lifelong diagnosis. Methods:PDA version of K-CIDI life-long diagnosis in part of major depressive disorder, alcohol, nicotine dependence and withdrawal were made. The reliability and validity of the PDA-K-CIDI was evaluated by examining 19 alcohol dependence patients, 30 patients with major depressive disorder and 30 community residents. Two psychiatric residents jointly interviewed by PDA-K-CIDI and inter-rater reliability were evaluated. Two psychiatric residents jointly determined clinical diagnoses using the Structured Clinical Interview for DSM-IV. The kappa value was calculated about agreement of two diagnoses to evaluate validity of PDA-K-CIDI. Results:The kappa values which indicates validity of the PDA-K-CIDI were 0.473-0.687 according to diagnostic criteria. The inter-rater reliability of the K-CIDI indicated kappa values ranging from 0.712-1 according to diagnostic criteria. Conclusions:The reliability and validity of the PDA-K-CIDI about major depressive disorder, alcohol, nicotine dependence and withdrawal were judged to be exceptionally acceptable. The PDA-K-CIDI was deemed to be appropriate for the epidemiologic study.