This study aims to determine the factors influencing the career preparation behavior of nursing students in the post-COVID-19 era and to provide a basis for preparation strategies to enhance nursing students’ nursing professionalism and career preparation behaviors. This is a descriptive cross-sectional study that measures major satisfaction, self-efficacy, nursing image, nursing professionalism, nursing image and intuition, and career preparation to identify factors influencing nursing students’ career preparation behavior in the post-COVID-19 era. An online survey was conducted to collect the data. The data were analyzed using descriptive statistics, Pearson’s correlation, and multiple regression analysis using the SPSS/WIN 25.0 program. A total of 240 students were included; most of them were female (86.3%) and between 21 and 25 years old (80%). The level of motivation to pursue nursing (F = 12.34, p < 0.001) and clinical practice satisfaction (F = 11.37, p < 0.001) showed statistically significant differences in career preparation behavior. Self-efficacy (r = 0.32), major satisfaction (r = 0.32), nursing image (r = 0.32), and nursing professionalism (r = 0.32) were positively correlated with career preparation behavior and significant (p < 0.001). According to the findings, nursing professionalism and image can be enhanced by providing career planning and counseling based on the student’s degree of comprehension and cognitive behaviors to nurture the professional and positive attitudes that are essential for a successful nursing career. Nursing schools need to incorporate a job portal, facilities, and a mentorship program to help nursing students prepare for their careers.