A 30-year-old man with a left testicular swelling was referred to our hospital. We performed a left high orchiectomy based on a diagnosis of clinical stage II testicular cancer. Pathological specimens of the left testis showed seminoma. The patient underwent three courses of combined chemotherapy. The retroperitoneal lymph nodes were dissected and there were no viable cancer cells. Twelve years later a right testicular tumor was discovered. The patient underwent a right high orchiectomy. Pathological specimens of the testis showed seminoma, and the patient was treated with prophylactic irradiation. One year after discharge a metastasis was found at a left supraclavicular fossa. The patient was treated with combined chemotherapy and irradiation. Six months after the treatment he complained of dyspnea. We diagnosed the condition as pleuritis carcimatosa. Two days after irradiation to the left thorax the patient suffered a sudden and fatal cardiac arrest. Autopsy survey revealed pericarditis as a result of a direct invasion of visceral pleural metastasis.