A 62-year-old man with left chest pain had left pleural effusion pointed out on a chest radiograph. Chest CT scans showed multiple nodules on the left parietal pleura and pleural effusion. He was referred to our hospital and we performed thoracoscopic examination. Malignant pleural mesothelioma (biphasic type) was diagnosed, based on the pathological findings of a parietal nodular mass, including immunohistological analysis. Chemotherapy using carboplatin and pemetrexed reduced the size of tumor and left pleural effusion. This is a rare case with atypical CT findings of malignant pleural mesothelioma.