We report on the detection of a primitive cardiac lymphoma revealed by a cerebral vascular accident in a context of deterioration of the general state with fever. The diagnosis of the cerebral vascular accident was verified by the brain scan. The echocardiography, in particular the transesophageal ultrasound, suggested the diagnosis of cardiac lymphoma due to the existence of an inhomogeneous multilobar mass invading the right ventricle and largely encompassing the right auricle. The histologic diagnosis of a malignant non-Hodgkin's lymphoma of type B malignancy was confirmed by anatomopathology. The evolution was, unfortunately, rapidly unfavorable, with the patient dying in a state of cerebral suffering despite a combination treatment of chemotherapy and radiotherapy.