Objectives This study aimed to lay the groundwork for enhancing the ethical decision-making confidence of nurs-ing students by identifying factors influencing this competence. Methods The study participants were 180 second-year nursing students from two universities in J Province. They were surveryed from January 5 to 15, 2024 using questionnaire. The data were analyzed using descriptive sta-tistics in the SPSS/23.0 program, in addition to an Indepent t-test, Pearson correlation coefficients, and stepwise multiple regression. Results The results are as follows. First, nursing students’ ethical decision-making confidence had a significant positive correlation with ethical values (r=.597, p<.001), ethical sensitivity (r=.589, p<.001), and nursing pro-fessionalism (r=.528, p<.001). Second, the factors influencing participants’ ethical decision-making confidence were ethical values (β=.332, p<.001), ethical sensitivity (β=.220, p=.009), nursing professionalism (β=.215, p=.003), and awareness of the Korean Nurses Code of Ethics (known) (β=.177, p=.040), in that order. These varia-bles explained 45.1% of nursing students’ ethical decision-making confidence. Conclusions This study is meaningful as it identified factors that affect the ethical decision-making confidence of lower-grade nursing students. To improve lower-grade nursing students’ confidence in ethical decision-mak-ing, it is necessary to impart appropriate ethical values, improve ethical sensitivity and nursing professional in-tuition, and develop curriculum and programs for accurate recognition of the Korean Nurses Code of Ethics, tail-ored to the level of the target audience. Various learning methods that take these factors into account will be needed.