Pericardial malignant mesothelioma is a rare and highly lethal cardiac neoplasm. A 28-year-old man presented with complaints of effort dyspnea and general fatigue. Chest radiogram showed cardiac tamponade and bilateral pleural effusion. The pericardial effusion was hemorrhagic, despite showing class III on cytology. CT scan, echocardiography and Ga scintigraphy could not detect the cause of pericarditis. Anti-tuberculosis therapy and steroids were without effect. Pericardiectomy and pericardial drainage were performed by the thoracoscopic technique. Despite the treatments mentioned above, the pericardial effusion gradually increased. On thoracotomy by median sternotomy, a diffuse mass with a jelly-like consistency was found to be proliferating and obliterating the pericardial space. The tumor was not resected. The diagnosis of pericardial mesothelioma of epithelial type was confirmed by histological and immunohistological studies. He died of cardiac failure five months after admission.