Primary tumors of the heart are uncommon. 75% of these tumors in the adult are benign and 25% are malignant. Angiosarcoma was the most frequent malignant tumour. 75% occurred on the right side, especially in the right atrial. This tumour was generally discovered in post-mortem because the non specificity of functional symptomatology. Echocardiography is the first non invasive tool for diagnosis and evaluation of cardiac mass. Angiosarcoma was associated with an unfavourable outcome. We reported a case of an atrial angiosarcoma revealed by transoesophageal echocardiography in a 42 years old woman.