To assess whether accounting transparency has improved in Korea following the adoption of international accounting standards, the authors analyzed financial statement data from non-financial companies in the Korean capital market over the period 2000–2020, considering the year 2011 when IFRS was introduced. The authors examine earnings management using discretionary accruals estimated from the modified Jones’ model and the model by Kothari et al., which are most actively used in this study. Statistically significant differences were confirmed in the regression analysis of analysis defects, modified Jones’ model (DA1), the model by Kothari et al. (DA2), modified Jones’ model of absolute values (ADA1), and the model of absolute values by Kothari et al. (ADA2). This research is a time-series analysis before and after the implementation of IFRS. The research covers ten years from 2011, the time of mandatory introduction. Nevertheless, it is difficult to measure the differences due to the implementation of IFRS.