Primary cardiac lymphoma (PCL) is among the rarest heart neoplasms. Its estimated incidence is about 1%-2% among primary cardiac tumor and 0.5% of extranodal lymphoma. It usually causes heart failure, pericardial effusion, tamponade, and arrhythmias. Prognosis is poor; treatment is combined medical and surgical. We described the case of a 62-year-old male with PLC that presented with syncope and cardiac tamponade, submitted to R-CHOP therapy because of failure of surgery. Clinical state is stable 3 months after diagnosis and first chemotherapy cycle.