Cor triatriatum dexter is a very rare congenital abnormality in which the right atrium is divided into two chambers by a membrane. In this abnormality, there is a high incidence of associated congenital abnormalities, particularly of the right heart. In this case study, a 67-year-old man with Ebstein's anomaly, atrial septal defect, and cor triatriatum dexter is presented and echocardiography is discussed as a noninvasive diagnostic tool.