Ectopic thyroid tissue is a rare congenital anomaly that results from multiple events during development. The ectopic thyroid may lie in several human organs including the tongue and mediastinum. It is rarely seen as an intracardiac mass. We report the case of a patient with an intracardiac mass diagnosed by echocardiography. The pathology of the mass was compatible with ectopic thyroid tissue with no signs of malignancy.