Background: Sarcomas are the most prevalent type of malignant primary cardiac tumor. Clinical presentation differs according to the size and location of the tumor and involvement of other structures.Case presentation:In this article, we present a 38 years old lady as a case of primary cardiac angiosarcoma with a huge challenge in diagnosis and management of the disease. On the 4thof June 2020, she emergently presented to the hospital with the chief complaint of cough and tachypnea, diarrhea, and malaise, and a history of blunt chest trauma three weeks ago. Based on the presentation and transthoracic echocardiography which was compatible with cardiac tamponade, emergent pericardiocentesis was performed. The first imaging showed bilateral pleural effusion, pericardial effusion, and no significant parenchymal lung involvement, which was not compatible with rheumatologic diseases or COVID-19. Based on cardiac CT angiography and evidence of dye entrance to the peri-right atrial area, right atrial free wall rupture was suspected as the cause of the massive pericardial effusion. Following multidisciplinary consensus, she underwent cardiac surgery; in addition to the 3*3 cm right atrium free wall rupture repair, concomitant sampling from the lung nodules, lymph nodes, pericardium, and also the surrounding tissue of the right atrium ruptured defect was performed. Based on immunohistochemistry, the diagnosis was compatible with cardiac angiosarcoma with metastasis to the lung. Due to the advanced stage of the tumor, oncologists advised against chemotherapy or radiotherapy and she went through palliative care. Finally, after a 53-day ICU stay and due to right-sided heart failure, the patient unfortunately died.Conclusion: COVID-19 pandemic has brought diagnostic challenges regarding differentiating SARS-CoV-2 infection from other diagnostic entities. On the other hand, due to the rarity and fatality of primary cardiac angiosarcomas, early diagnosis and possible management seem crucial for prolonged survival. Involving cardiac angiosarcoma in the initial differential diagnosis could warrant timely diagnosis and assessment of various therapies for cure or palliative care.