Data on 54 persons who died of acquired immunodeficiency syndrome were reviewed for lesions of the heart. These persons met the criteria of the Centers for Disease Control (Atlanta) for acquired immunodeficiency syndrome. Pathologic changes were seen in 30 patients (55%). Changes were seen in the endocardium (17%), myocardium (83%), and epicardium (3%). The most frequent finding was lymphocytic myocarditis. Six of these were due to Toxoplasma myocarditis. Only one patient succumbed to cardiac arrest.