Body image dissatisfaction (BID) is increasing among U.S. men and is associated with body-enhancing behaviors that threaten physical health, such as excessive dieting and exercising. A research gap was identified about the relationships between men's body image dissatisfaction, body-enhancing behaviors, and the possible mediating effect of self-esteem. The purpose of this study was to examine the relationships among body image dissatisfaction, body-enhancing behaviors, and self-esteem in adult males. Sociocultural and social comparison theory served as the theoretical frameworks for this study, which included 103 participants recruited through a university participant pool and gyms. Participants completed questionnaires including the Body-Esteem Scale, Rosenberg Self-Esteem Scale, Exercise Dependence Scale-21, Revised Restraint Scale, and a demographic questionnaire. Correlational and regression analyses were conducted to determine the relationships between all constructs and to test self-esteem as the mediating variable. A mediation model showed a relationship between dieting and self-esteem and BID in that high BID was related to low self-esteem. However, self-esteem did not mediate the relationship between diet and exercise. Findings indicated a significant relationship between higher BID and lower self-esteem. Results also indicated a significant relationship between BID and dieting. Results may be used to improve the lives of men affected by BID by informing them about factors that may affect BID and/or self-esteem. Enhancing the understanding of males' low self-esteem and body image may help researchers and practitioners develop more effective interventions.