Primary cardiac tumors are extremely rare. Among them, malignant tumors constitute approximately 15% of primary cardiac tumors. Angiosarcomas are the most frequent. They often appear as mural masses in the right atrium and completely replace the atrial wall and fill the entire cardiac chamber. We report an unusual case of angiosarcoma in a 75-year-old woman with a cystic appearance, located in the left atrium and causing critical mitral stenosis. (Echocardiography, ****;**:E1-E2).