Thrombi in the right atrium (RA) are infrequent, and are rarely diagnosed before death. In addition, right heart thrombi are frequently associated with major pulmonary thromboembolism, and carry a very high risk of mortality, and therefore, require accurate diagnosis and prompt treatment. RA thrombi are generally associated with dilatation of the atrium, a low cardiac output state, intracardiac catheters, such as endocardial pacemakers and central venous hyperalimentation catheters, recent cardiac surgery, involving the atrium, and peripheral deep vein thrombosis. In addition, some systemic diseases, such as malignant tumors, amyloidosis and nephrotic syndrome, have been shown to contribute to the formation of an intracardiac thrombus. Echocardiography is valuable in the diagnosis of RA thrombi. There are some options in the treatment of RA thrombi, such as anticoagulant therapy using heparin, thrombolytic therapy and surgical removal. However, there is still adverse criticism as to the selection of the correct treatment method. A patient with RA thrombi, who presented with sudden cardiogenic shock, was diagnosed by two-dimensional echocardiography. He had been in a prolonged bed-ridden state because of quadriparesis caused by an injury to the cervical spine. The RA thrombi were successfully treated with anticoagulant and thrombolytic agents.