The cardiomyopathies constitute a group of diseases with direct involvement of the heart muscle itself, and is a significant cause of morbidity and mortality. The World Health Organization (WHO) and the International Society and Federation of Cardiology (ISFC) have promulgated a classification taking into consideration the etiology and pathophysiology, which includes dilated cardiomyopathy, hypertrophic cardiomyopathy, arrhythmogenic right ventricular cardiomyopathy, restrictive cardiomyopathy, and unclassified cardiomyopathies. Over 25 causes are associated with the development of the cardiomyopathies. The classification of the diseases affecting the heart and causing the cardiomyopathies is presented including the highlights of the most important data for diagnosis and management of each one.