The purpose of this study was to investigate the effect of professionalism, critical thinking process, and
ethical decision making on nursing students' nursing ethical values. Data collection was from June 1 to
June 15, 2017, and the subjects were 150 nursing students attending Y University. The collected data were
analyzed using SPSS WIN 21.0. The results showed that factors affecting ethical values were ethical decision making(t=4.414, p<.001) and ethical concept{dum1 t=-2.055, p<.005, dum2 t=-4.529, p<.001)}, and
statistically significant. Ethical decision making was found to be an effective meditator value and
statistically significant in the effect of professionalism(F=12.242, p<.001) and critical thinking(F=13.020,
p<.001) on nursing ethical values. The results show that ethical decision making and ethical concepts
influence the establishment of nursing ethical values, and professionalism and critical thinking influence
ethical decision making and ultimately influence of nursing ethical values. Therefore, it is necessary to
develop a nursing ethics education program in curriculum or comparative course in which nursing students
can establish and grow firm and positive ethical values.