Résumé : We present a very rare case of a neonatal multiple haemangiomatosis with a cystic interventricular cardiac haemangioma. An anechoic cyst of 10 mm of diameter, located in the superior third of the interventricular septum was found by foetal echocardiography at 30 weeks of pregnancy. The baby was born at 39 weeks of pregnancy and the skin was covered with multiple purple cutaneous haemangiomas. As neonatal haemangiomatosis may be associated with visceral haemangiomas, the diagnosis of cardiac haemangioma was considered and transthoracic echocardiography revealed a translucent cyst consistent with this diagnosis. At 6 months of age, the cardiac mass was barely visible and most cutaneous lesions had regressed without treatment. Cardiac haemangiomas must be considered in the diagnosis of cystic masses, and the present case emphasizes the tendency towards spontaneous regression of these lesions. © 2011 The Author.