Purpose: This study attempted to determine the effects of a healthcare volunteer program on nursing students’ professionalism, self-leadership, self-efficacy, major satisfaction, and volunteer activity satisfaction. Method: This study collected data before and after the implementation of a healthcare volunteer program consisting of 4 hours of education including 3-hour lecture and 1-hour practice, and 70 hours of medical volunteer activities over a period of 2 months from January to February 2024. The subjects who participated in this study were 55 freshmen and sophomore in nursing students. The effectiveness of the program was analyzed using the IBM SPSS WIN program, and the effects of nursing professional intuition, self-leadership, self-efficacy, and major satisfaction were analyzed using paired t-tests, and volunteer activity satisfaction was analyzed using mean and standard deviation. Results: In this study, the experimental group's nursing professionalism increased from 115.35±11.85 points to 122.91±12.46 points (t=3.26, p=.002), and self-leadership increased from 64.27±7.16 points to 66.98±7.41 points (t=2.10, p=.041), self-efficacy increased statistically significantly from 65.69±8.70 points to 69.45±10.45 points (t=2.31, p=.025). However, major satisfaction increased from 24.24±3.75 points to 24.78±4.06 points, but there was no statistically significant difference (t=0.72, p=.472). In this study, volunteer activity satisfaction was 96.90±13.67 points, which when converted to a perfect score of 100, was 86.52 points. Conclusion: The results shows volunteer activities at medical institutions can increase nursing students' professionalism, self-leadership, and self-efficacy before clinical practice. Therefore, we suggest volunteer work at medical institutions to increase nursing students' professional intuition, self-leadership, and self-efficacy.