Cardiac infiltration by lymphoma is a rare finding during life. However, metastatic deposits are frequently found at postmortem in patients with malignant lymphoma. In the past, this may have been due to difficulties in imaging the heart. Today, 2-dimensional echocardiography is a widely used, safe, noninvasive test which allows excellent spatial imaging of cardiac structures. We report a case of extensive primary myocardial and pericardial involvement by malignant lymphoma in which echocardiography was used to document the diagnosis and follow the response to chemotherapy.