Objectives: In the treatment of schizophrenia, treatment compliance is an important prognostic factor. As insight has a significant impact on treatment compliance, an appropriate assessment of insight is essential in the treatment of schizophrenia. This study examined the reliability and validity of the Korean version of Birchwood Insight Scale (BIS). Methods: Fifty seven adult patients diagnosed with schizophrenia according to DSM-5 were recruited from a university hospital. They were evaluated using the Positive and Negative Syndrome Scale (PANSS), The Scale to Assessment Unawareness of Mental Disorder (SUMD) and BIS. Explorative factor analysis was performed to examine the construct validity of the Korean version of BIS. Concurrent validity was evaluated by a comparison with the PANSS G12 item and SUMD. The test-retest correlation was evaluated to examine the test-retest reliability. Multiple regression analysis was performed to examine the variables affecting insight. Results: Explorative factor analysis showed that the Korean version of BIS was composed of 2 factors, which are ‘Awareness of symptoms’ and ‘Awareness of illness and need for treatment.’ The Korean version of BIS was reliable in terms of the internal consistency. Concurrent validity with the PANSS G 12 item and SUMD was statistically significant. The test-retest reliability was also statistically significant. Multiple regression analysis showed that the PANSS negative factor affects the BIS score, indicating that negative symptoms of schizophrenia may impair insight of the illness. Conclusions: This study suggests that the Korean version of BIS is a valid and reliable tool for assessing the insight of patients with schizophrenia.