OBJECTIVE: The Childhood Trauma Questionnaire (CTQ) is perhaps the most widely used and well-studied retrospective measure of childhood abuse or neglect. This study tested the initial reliability and validity of a Korean translation of the Childhood Trauma Questionnaire (CTQ-K) among non-psychotic psychiatric outpatients. METHODS: The CTQ-K was administered to a total of 163 non-psychotic psychiatric outpatients at a university-affiliated training hospital. Internal consistency, four-week test-retest reliability, and validity were calculated. A portion of the participants (n=65) also completed the Trauma Assessment Questionnaire (TAQ), the Impact of Events Scale-Revised, and the Dissociative Experiences Scale-Taxon. RESULTS: Four-week test-retest reliability was high (r=0.87) and internal consistency was good (Cronbach's alpha=0.88). Each type of childhood trauma was significantly correlated with the corresponding subscale of the TAQ, thus confirming its concurrent validity. In addition, the CTQ-K total score was positively related to post-traumatic symptoms and pathological dissociation, demonstrating the convergent validity of the scale. The CTQ-K was also negatively correlated with the competence and safety subscale of the TAQ, confirming discriminant validity. Additionally, we confirmed the factorial validity by identifying a five-factor structure that explained 64% of the total variance. CONCLUSION: Our study indicates that the CTQ-K is a measure of psychometric soundness that can be used to assess childhood abuse or neglect in Korean patients. It also supports the cross-cultural equivalence of the scale.