Although career preparation is an important factor in making correct career decisions and increasing job satisfaction, nursing students lack consideration and preparation for their career path when choosing a major. The purpose of this study was to identify the relationships among career decision-making self-efficacy, career outcome expectation, and career consciousness maturity on the behavior of nursing students in preparing for their careers. We collected data using structured questionnaires from 95 nursing students in C city from June 1 to June 20, 2018. We analyzed the data using the IBM SPSS/WIN 23.0 program for descriptive statistics, independent t test, oneway ANOVA, Pearson’s correlation coefficient, and multiple regression. As a result, the factors influencing the career preparation behavior of nursing students were career decision self-efficacy (β = .35, p < .001) and career consciousness maturity (β = .30, p = .003), and the explanatory power of these variables was 37%. Based on these results, it was required to develop programs to strengthen career decision-making self-efficacy and career consciousness maturity. In order to improve career decision-making self-efficacy, a program should be developed to improve confidence in solving problems by providing career opportunities. In addition, in order to strengthen career consciousness maturity, a career road map for each grade should be constructed, as well as systematic career counseling and employment capacity enhancement programs.