A 53-year-old man was admitted to our hospital for back, left shoulder and upper limb pain. Chest radiography and CT on admission revealed right pleural effusion and a focal plate-like thickening of the major fissure. Pleural effusion cytology revealed adenocarcinoma, which was diagnosed as non-small-cell lung cancer with bone metastasis. The patient suffered from DIC, melena and multiple cerebral infarctions during chemotherapy and died on the eighth day of the second course of chemotherapy. Autopsy revealed a pseudomesotheliomatous adenocarcinoma covering the pleura of the right middle lobe, systemic thromboembolism and vegetations on the aortic valves due to nonbacterial endocarditis. Pseudomesotheliomatous adenocarcinoma of the lung, a rare form of lung cancer, complicated with DIC and nonbacterial endocarditis, is reported.