Children with cardiomyopathy represent the most dismal outcome of any group of diseases followed by pediatric cardiologists, with up to 40 percent of infants and children with symptomatic cardiomyopathy failing medical or surgical management in the first year following diagnosis. For 57 percent of children with cardiomyopathy, no etiology is known. Although pediatric cardiomyopathy is common, there is considerable variation in its causes. Therefore, for any specific etiology, no center of pediatric cardiology sees a sufficient number of patients to make major advances in understanding this group of diseases. The registry was developed to collect and organize all relevant data on the condition. Data accrued by and reported by the registry should lead to increased awareness and knowledge of pediatric cardiomyopathy and its causes, as well as the development of new diagnostic and therapeutic approaches.