The aim of this study is to examine the psychometric properties of the Korean version of the Post-traumatic Stress Disorder Checklist for DSM-5(PCL-5). To this end, online surveys were conducted two times at 1-year interval with 1,077 Korean adults at time 1, and 563 Korean adults at time 2. First, as a result of confirmatory factor analysis, factor 1 was found to be not acceptable, while factor 4, 6 and 7 were found to be acceptable and showing the best model fit in the order of factor 7, 6, 4. Second, as a result of examining reliability of Korean version of PCL-5, Korean version of PCL-5 showed good reliability. Third, as a result of correlation analysis with K-PC-PTSD-5 and sub-factors of BSI-18, Korean Version of PCL-5 had positve correlation with both K-PC-PTSD-5 and BSI-18. Fourth, PTSD symptoms measured by the Korean version of PCL-5 at time 1 properly predicted PTSD, depression, anxiety, and somatization symptoms at time 2. Fifth, discrimination power of PCL-5 for screening PTSD group and best cut-off score were confirmed by ROC anlaysis. As a result of the longitudinal validation of Korean version of PCL-5, it was found that this scale is a reliable and valid measure for Korean adults. This study differs from previous validation studies in that the Korean version of PCL-5 can predict not only PTSD symptoms but also PTSD-related symptoms such as depression, anxiety, and somatization, and that the best cut-off score for distinguising PTSD symptom group was confirmed.