A 65-year-old man was admitted with dyspnea. Chest radiograph showed left pleural effusion and chest CT scan revealed multiple left pleural masses. The diagnosis of malignant pleural mesothelioma was made by CT-guided needle biopsy. He received the combination chemotherapy with pemetrexed and carboplatin. The day after initiating chemotherapy, he had fever and dyspnea. Chest CT scan showed diffuse ground glass opacities mainly in the right lung, suggestive of drug-induced interstitial pneumonia. Corticosteroid pulse therapy was started, but he died of respiratory failure 10 days after beginning chemotherapy. This is apparently the first reported case of pemetrexed-induced acute lung injury.