Methysergide ( Sansert ) has been associated with numerous fibrotic disorders. In particular, multiple cardiac lesions have been described in cases where methysergide was thought to have played a causative role. A patient is described who presented with cardiac findings suggestive of acute myopericarditis . An inflammatory myocarditis was subsequently excluded by endomyocardial biopsy. Hemodynamic findings suggested the presence of constrictive pericarditis or restrictive cardiomyopathy, or both. Radiographic evidence of constrictive pericarditis and biopsy evidence of endocardial fibrosis were documented in this patient with a long history of interrupted methysergide therapy.