Hypertrophic cardiomyopathy (HCM) is a genetically inherited disease with a wide spectrum of phenotypic presentations. It is crucial to establish an early diagnosis and identify patients at high risk for sudden death. Cardiac magnetic resonance can provide subclinical diagnosis, quantification of severity of known disease, risk stratification, and assessment of response to therapy for HCM. This pictorial review summarizes the main magnetic resonance appearances of HCM and its differential diagnosis.