Purpose: Nursing is regarded as a female-dominated profession. However, the number of Korean males entering the field of nursing is increasing. This study examines which of the following factors influence professionalism in male and female student nurses: area of nursing, gender identity, gender stereotypes, satisfaction with the field, emotional intelligence, and interpersonal relationships. Method: In total, 133 male and 293 female student nurses were selected from four Korean provinces between July 2013 and February 2014 to participate in this study. The data were analyzed with descriptive statistics, t-tests, ${chi}^2$-tests of independence, and multiple regression analyses using SPSS/Win 20 software. Results: In males, 47.4% of variance in nursing professionalism was accounted for by grades, interpersonal relationships, gender stereotypes, and satisfaction with the field. In females, 41.9% of variance in nursing professionalism was accounted for by satisfaction with the field, interpersonal relationships, area of nursing, age, emotional intelligence and grades. Common factors that influenced both genders included satisfaction with the field, interpersonal relationships and grades. Conclusion: Although males and females revealed no significant differences in overall mean scores of nursing professionalism, several factors influencing nursing professionalism did differ by gender. Therefore, gender-specific nursing educational and training programs may be necessary to promote professionalism among student nurses.