Bilateral diaphragmatic paralysis is a rare disease. It is caused by trauma, cardiothoracic surgery, neuromuscular disorders, corvical spondylosis, and infection. A 60 year-old male patient developed bilateral diaphragmatic paralysis after an on-bloc resection of thymic carcinoma which invaded the right upper lobe, pericardium, superior vena cava and innominate vein. Severe respiratory difficulty developed and ventilator weaning was impossible. We performed bilateral diaphragmatic plication. After the operation, satisfactorily ventilator weaning and sleeping in supine position were possible; therefore, we report this case.