Background: Primary cardiac angiosarcoma is a rare cardiac tumor. Most of them grew in the right atrium, often invading the superior vena cava and pericardium. The clinical symptoms of majority patients may present right heart failure, superior vena cava obstruction, and even pericardial tamponade. Case presentation: In this case report, we presented a 76-year-old man presented with chest tightness, fatigue, pericardial effusion, and arrhythmia. The transthoracic echocardiography (TTE) showed that a mass in the right atrium. Histopathology and immunohistochemistry confirmed the diagnosis of angiosarcoma. The patient was discharged from hospital after surgery. Conclusions: For the patients with early stage cardiac angiosarcoma without evidence of metastasis, radical resection of the primary tumor remains the most important approach for optimal survival.