Objective : Health psychology focuses on health promotion and disease prevention. One of the factors that is related to the promotion of mental health is the sense of humor which can be influenced by the components of psychological capital. This study aims to predict the psychological capital dimensions based on the humor styles among the medical students of Tarbiat Modares University. Method : This study is descriptive correlational and the statistical population consisted of all medical students of Tarbiat Modarres University. The participants of the study were 120 who were selected through volunteer sampling. Data were collected by the Luthans Psychological Capital Inventory and Martin’s Humor Style Scale. Data were analyzed through Pearson’s correlation coefficient and multiple regression analysis. Results : Results showed that self-efficacy and hopefulness have a positive significant relationship with adaptive humor styles, but the relationship between self-efficacy and hopefulness with maladaptive humor styles was negative. Also, there was no significant relationship between resilience and all four humor styles. Conclusion : By strengthening adaptive humor styles, it is possible to increase the psychological capital of students to help their mental health.