In a recently published post-mortem series the incidence of cardiac lesions in malignant lymphoma was estimated at about 8.7%. These lesions rarely produce specific cardiac symptoms; they usually are late manifestations of a disease with multiple secondary lesions or are discovered at autopsy. In most patients the lesions are not limited to the heart but represent the extension to that organ of a malignant lymphoma. We observed two cases of cardiac lesions secondary to malignant non-Hodgkin lymphoma and we were able to evaluate their response to chemotherapy. In the first patient the cardiac symptoms revealed the lymphoma; in the second patient the cardiac involvement was discovered 4 years after the lymphoma was diagnosed. In both cases the cardiac lesions were detected by two-dimensional echocardiography. They presented as polypoid masses filling the right atrium and associated with periaortic thickening in the first case, and as a large heterogeneous mass including a tricuspid valve leaflet and extending to the free wall of the right ventricle in the second case. Pericardial effusion was present in the two patients. These echocardiographic findings were confirmed computerized tomography and catheterization. In the first case, followed up for one year, the echocardiographic images reverted to normality after chemotherapy. The second patient, unfortunately, did not respond to chemotherapy and deteriorated rapidly.