Patients (3) with chronic complete AV [atrioventricular] block had granulomatous giant cell myocarditis (GGCM) at autopsy. In 1 patient an unusual clinical course led to more extensive investigation including echocardiography which revealed ventricular septal abnormalities. A review of the literature is presented. Although GGCM is a rare disease echocardiography may be a useful screening procedure in patients with AV block especially in the presence of immunological disorders.