Body dysmorphic disorder (BDD) is associated with severe comorbidity and impairment. Muscle dysmorphia (MD) is a subtype of BDD which has rarely been assessed outside of undergraduate student samples. Further, there are limited data comparing MD to other psychiatric disorders, including BDD. Thus, the aim of the current study is to explore differences in symptom severity and conformity to masculine norms in men diagnosed with BDD or MD. Men from the greater Boston, Massachusetts area completed a one-time assessment, which included clinician-based structured interviews and self-report questionnaires assessing MD symptom severity, BDD symptom severity, and conformity to traditional masculine norms. The sample was N = 30 men (MD: n = 15; BDD: n = 15). Statistically significant medium to large effects emerged with the MD group experiencing greater MD and BDD symptom severity, and positive attitudes towards the use of violence to solve problems. Although not reaching statistical significance, additional medium-to-large effects also emerged with the MD group reporting greater emotional restriction/suppression, heterosexual self-presentation, and desired sexual promiscuity compared to the BDD group. Findings suggest that men diagnosed with MD may experience greater MD/BDD symptom severity and endorsement of some components of 'traditional' masculine norms, compared to men diagnosed with BDD. Results may suggest that addressing some forms of rigid masculine norms (e.g., use of violence) in therapy could be useful in treating MD; however, additional research comparing clinical samples of men with MD and BDD are needed to guide the nosology, assessment, and treatment of MD.