Three cases with valve thrombosis of St. Jude Medical prosthesis (SJM valve) are reported. Incidence of valve thrombosis of SJM valve was 0.15%/patient-year. Cineradiography was useful to make the diagnosis. SJM valves were implanted with the hinges anatomically oriented in mitral position, and in both aortic and tricuspid positions with the leaflet opening parallel to the ventricular septum. Therefore, we recommend that SJM valve should be placed with the hinge antianatomically oriented in mitral position, and in both aortic and tricuspid positions with the leaflet opening to be perpendicular to the interventricular septum, respectively.