Endomyocardial biopsy has found wide application as a diagnostic tool in the practice of cardiology and is of great clinical use in selected cardiac disorders. It is indispensable in the management of cardiac transplant recipients and has become increasingly valuable in the diagnosis of myocarditis and certain cardiomyopathies. Technical difficulties have been overcome, and the procedure is straightforward and of low risk in experienced hands. It is hoped that advances in endomyocardial biopsy will lead to a greater ability of physicians to diagnose and treat cardiac disease.