Objectives: The purpose of this study was to evaluate the risk factors associated with grade retention and national exam failure in the school of dentistry. Methods: The subjects of this study were students who enrolled at the school of dentistry from 2013-2017. Univariable and multivariable analyses were examined through logistic regression analysis. The potential contributing factors of grade retention and national exam failure include: graduated high school, graduated college, major, admission score, admission type, decision type, gender, age at the time of admission, and dental school Grade Point Average(GPA). Results: Higher dental school score correlated with lower risk of grade retention or failing national exam, but undergraduate GPA was not related to the risk of national exam failure. Older students and specific admission types had higher risk of repeating school year. Conclusion: It's important to provide focused guidance for high-risk students, especially those with average of dental school score below 80, to prevent grade retention or national exam failure. Developing a student achievement monitoring system can help prevent grade retention or national exam failure.