Recent advances in the surgical treatment of congenital disorders of the heart have necessitated an accurate preoperative diagnosis. Right heart catheterization has become widely accepted as a research tool and diagnostic test to detect the heart diseases, especially in the congenital heart anomalies. Right heart catheterizations were carried out in 50 cases of congenital heart diseases at Department of Thoracic and Cardiovascular Surgery, , Kyungpook National University Hospital, during the period of June, 1975 through September 1978.