Total 11 cases of tricuspid atresia were diagnosed radiographically at Seoul National University Hospital in recent two years since 1979. Some characteristic radiological findings were analyzed in chest P-A view and cineangiographies of right atrium and left ventricle. The results are as follows; 1. Among the 11 cases, 4 cases were male and 7 cases were female. Age distribution was from 2 months to 19 years and mean age was 3 1/2 years. 2. Anatomaic types of those cases according to Keith's classification were as follows; type Ia in 2 cases, type Ib in7 cases, type Ic 1 case and type IIb in 1 case. 3. The cineangiographic features of tricuspid atresia are sequential filling of contrast media in the order of right atrium, left atrium, and left ventricle, and triangular filling defect at the base of the heart in all cases, and right atrial dimple in two cases. 4. It is essential for the diagnosis of tricuspid atresia to undertake cineangiographies of right atrium and left ventricle, and the interrelationship of great arteries.