Purpose: The purpose of this study was to identify the effects of nursing professionalism, satisfaction with major, and self-leadership on nursing student career preparation behavior. Methods: Data were collected from August 1 to August 31, 2014. Participants were 400 students who completed self-report questionnaires covering career preparation behavior, nursing professionalism, satisfaction with major and self-leadership. The SPSS/WIN/PC 21.0 program was used for descriptive statistics, t-test, ANOVA, Pearson correlational coefficients and stepwise multiple regression. Results: The average scores for career preparation behavior, nursing professionalism, satisfaction with major, and self-leadership were 2.51, 3.80, 3,89, and 3.51 respectively. There were positive correlations among career preparation behavior, nursing professionalism, satisfaction with major, and self-leadership. Age, academic year, nursing professionalism, self-leadership, general satisfaction in satisfaction with major were significant predictors of career preparation behavior. Conclusion: It is necessary to provide career educational programs considering according to the academic year of nursing students and to develop educational programs to improve the nursing professionalism of nursing students.