Purpose : This study aimed to identify the effects of daytime sleepiness, depression, and quality of life on the academic achievement of nursing students. Methods : The subjects of the study were 250 students attending two nursing universities located in the City of C or Y. The study was conducted from October 17, 2022 through October 31, 2022 by using the self-reported questionnaire. The collected data were analyzed by using descriptive statistics, independent t-test, one-way ANOVA, Pearson’s correlation coefficient, and the hierarchical multiple regression using the SPSS win. 26.0 program. Results : The academic achievement of the nursing students was negatively correlated with daytime sleepiness (r＝-.27, p＜.001), depression (r＝-.38, p＜.001). however it was positively correlated with quality of life (r＝.49, p＜.001). The most influential factor for the academic achievement was the quality of life (β＝.37, p＜.001), followed by daytime sleepiness (β＝-.13, p＝.031), and depression (β＝-.13, p＝.044), which together explained their academic achievement up to 32.4%. Conclusion : In order for the nursing college students to successfully perform their duties as professional nurses after graduation, effective strategies are needed to reduce daytime sleepiness and depression and improve the ...