In a heart transplant patient who had undergone several endomyocardial biopsies, ultrasound examination revealed severe left ventricular dysfunction after a stroke. Coronary angiography showed a distal left anterior descending artery fistula to the right ventricle. Left ventricular angiogram showed apical dyskinesia. The electrocardiogram and angiographic changes were thought to be due to a myocardial infarction secondary to a postendomyocardial biopsy hematoma, which should be added to the list of possible complications involved in endomyocardial biopsy.