Randomized clinical trials are essential for the development of an evidence base for treating virtually all medical conditions. Opportunities for randomized clinical trials in pediatric cardiomyopathy exist in many areas, including determination of the utility of biomarkers in diagnosis and management, preventative strategies for children at risk for cardiomyopathies, pharmacogenomic studies, and drug or device treatment studies. Because of the rare nature of pediatric cardiomyopathies, many obstacles exist to the implementation of clinical trials in this entity. Obstacles include realistic enrollment targets, endpoint determinations, and funding of these very expensive kinds of trials. This review discusses each of these topics and provides some examples and some options for performing randomized clinical trials in children with cardiomyopathy. (C) 2010 Elsevier Ireland Ltd. All rights reserved.