A 63-year-old lady presented with syncope and atypical chest pain. Conventional two-dimensional (2D) contrast echocardiogram showed a highly vascular mass compressing the right atrium without direct communication. A real-time three-dimensional echocardiogram (RT3DE) revealed its outer spatial relationship with the surrounding structures and its inner heterogeneity as well. A chest computed tomography revealed a solid cardiac mass (6 x 7 cm(2)) arising from the right atrium and multiple pulmonary nodules. Histopathology of the pericardial fluid confirmed angiosarcoma. To our knowledge, this is the first report of histology-confirmed primary cardiac angiosarcoma, which was completely evaluated by conventional 2D, contrast, and RT3DE.