Though many publications in the field of myocarditis and cardiomyopathies have renewed interest in the value of endomyocardial biopsy, its role in the work-up of patients with cardiomyopathies, idiopathic arrhythmias and even ischemic heart disease, is still debated. Since its introduction in 1963 the technique has been developed with current routine use of a biventricular and even atrial approach. At the same time immunohistochemistry and molecular biology studies have greatly enhanced the information obtainable from myocardial samples. The authors report their experience and briefly review the pertinent literature on the current use of endomyocardial biopsy in the diagnosis and treatment of dilated, hypertrophic and restrictive cardiomyopathy, of idiopathic arrhythmias and in ischemic heart disease.