A 30-year-old woman was admitted to our hospital with severe shortness of breath. A transthoracic echocardiogram showed moderate pericardial effusion with a lesion in the right atrium, confirmed by chest CT scan and cardiac RMN. Pleural and middle lobe involvement occurred within one month. Middle lobe biopsy was performed and pathological examination confirmed the diagnosis of metastatic angiosarcoma. After two months, because of recurrent pleural effusions, chemical pleurodesis was performed. Chemotherapy was started but the patient died four months after the diagnosis. This case highlights the misdiagnosis at initial clinical presentation, available diagnostic approaches and therapeutic options for cardiac angiosarcoma.