Purpose: Many studies from the past have indicated that women tend to have lower selfesteem than men. This cross-sectional study looks for this tendency in a medical school in Korea, where men are still thought to comprise much of a dominating force despite the current growth in number of female students in student body. Along with the cross-examination of possible gender difference in self-esteem, the significant and relevant factors will also be sought and discussed. Methods: Questionnaires were obtained from 202 junior and senior students (125 male and 77 female students) in a medical school in Korea. Self-esteem was determined using the Rosenberg self-esteem scale (reliability = 86% in our study). Multiple regression analysis was used to determine gender difference in self-esteem and statistical relevance in each covariate. Results: There was no statistically significant difference in self-esteem between male and female medical students. Significant factors related to self-esteem include school rank, physical attractiveness, and depression, among which of them, depression was the strongest. Conclusion: Innate limitation of cross-sectional studies and evaluation of selected junior and senior students of a single medical school could possibly explain for the absence of gender difference in self-esteem in this study. Academic achievement and physical attractiveness are shown to be positive factors for self-esteem, while depression puts negative force in one s self-esteem.