Until recently, the only imaging technique for the diagnosis and management of hypertrophic cardiomyopathy (HCM) was two-dimensional echocardiography, and the use of cardiac magnetic resonance imaging (cMRI) was limited to patients with poor acoustic windows. Now, cMRI has gained an essential role in the diagnosis of HCM, providing superior visualization of myocardial hypertrophy—even in remote zones of the left ventricle—and visualization of subtle changes in thickness and contractility over time. The morphologic accuracy of cMRI allows for the differentiation of HCM from other pathologic conditions with hypertrophic phenotype. Moreover, cMRI sheds light on the in vivo fibrotic changes in cardiac ultrastructure, offering an important advantage in the understanding of pathologic mechanisms of the disease, allowing early identification, risk stratification, and timely therapeutic management.