Cardiomyopathies are chronic, progressive diseases of the myocardium which are classified into four categories: hypertrophic cardiomyopathy (HCM), dilated cardiomyopathy (DCM), restrictive cardiomyopathy (RCM) and arthythmogenic right ventricular cardiomyopathy (ARVC). Cardiomyopathies are often due to genetic factors, but there is developing evidence that inflammation and injury may contribute to their development. While the cause of a given cardiomyopathy may be identifiable, many can only be classified as idiopathic. Cardiac MRI is able to characterize cardiomyopathies by their morphologic and functional phenotype as well as by tissue characterization. The previously described MRI techniques used to study myocardial function (cine imaging, delayed enhanced imaging) can also be put to use in studying cardiomyopathies.