Persistent pericardial hematoma due to blunt chest trauma is extremely rare. We report a case of constricted myocardium resulting from a large, partially organized hematoma in the right cardiophrenic angle. The hematoma was assumed to be caused by an occupational accident 17 years before diagnosis. Constriction could only be controlled by complete removal of the fibrous posterior capsule of the hematoma, which covered the epicardium of the right heart.