Cardiomyopathies and their resultant systolic and diastolic heart failure remain the main cause of cardiovascular morbidity and mortality in both children and adults and are a frequent indication for cardiac transplantation. According to the American Heart Association 2005 Heart and Stroke Update, more than 26,000 deaths each year in the United States are caused by cardiomyopathy. Cardiomyopathy is second to coronary artery disease for the most common direct cause of sudden death in the United States and is a leading cause of heart failure. This article provides an overview of the pathophysiology, causes, signs and symptoms, diagnosis, and treatment of the different types of cardiomyopathies. Newer therapeutic modalities and pharmacologic interventions are discussed, with an emphasis on improving symptoms and long-term survival.