There have been several case reports, a total of 22 up to the present, of toxoplasma pericarditis. Out of them, in only a few cases the diagnosis was properly made with a proof of the microscopic presence of Toxoplasma gondii. This is the first report of toxoplasma pericarditis in which the presence of Toxoplasma gondii was detected by polymerase chain reaction of pericardial effusion. In addition, the previous reports will be reviewed, and compared to this present case. A 29-year-old woman, without immunosuppressant disorder, suffering from fever and orthopnea was admitted to our hospital. Blood chemistry findings indicated mild liver dysfunction and inflammation. Chest radiography showed cardiac enlargement. Electrocardiography showed sinus tachycardia and ST elevation. Echocardiography revealed a massive pericardial effusion. Pericardiocentesis demonstrated 638 ml of bloody fluid. Cytologic study of the fluid was class II for malignancy, and polymerase chain reaction to tuberculosis was negative. However, a high titer of the anti-toxoplasma antibody of 1: 20,480 (passive hemagglutination) indicated pericarditis caused by Toxoplasma gondii. Subsequently, Toxoplasma gondii was identified in the pericardial effusion by polymerase chain reaction. Clinical symptoms improved after pericardiocentesis, but 2 months later pericarditis recurred. Treatment was started with 800 mg acetylspiramycin daily but failed to improve the symptoms. Because of the development of pleuritis, treatment was changed to sulfadoxine 1,000 mg/pyrimethamine 50 mg. After the treatment with them, her symptoms improved. Only 22 cases of toxoplasma pericarditis have been reported worldwide and 15 of those cases were without immunosuppressant disorder. The usual symptoms at the onset of pericarditis without immunosuppressant disorder are fever, dyspnea and chest pain. Seven patients developed cardiac tamponade. Pericardiocentesis was performed in 8 cases and the pericardial fluid was hemorrhagic in 6. Pericardial thickening was detected in 5 cases. The diagnosis of toxoplasma infection is very difficult, because asymptomatic infection of Toxoplasma gondii is very common. Pericarditis is a disease difficult to confirm the etiology. Detection of Toxoplasma gondii in pericardial effusion by the polymerase chain reaction is very useful for its diagnosis.