A 3 year old boy presented with a cardiac murmur. Except for mildly impaired physical condition that was more likely due to asthmatic bronchitis, he was asymptomatic. Cardiac echocardiography disclosed a large tumor in the left atrium originating from the interatrial septum. The patient was immediately referred to surgery for excision of the tumor. Histological examination of the tumor showed a typical papillary fibroelastoma. The occurrence of a papillary fibroelastoma in a child is a rarity.