The aims of chest drainage after pulmonary resection are to evacuate fluid and air that accumulate in the pleural space and to obtain information on problems such as air leakage and postoperative bleeding. Although suction or water seal drainages are commonly used procedures, the use of digital monitoring system (Thopaz) is gaining popularity as an alternative of the procedures. We need to pay attention to postoperative hemorrhage, chylothorax, infection, and air leakage. Chest X-ray is essential to check the position of the drainage tube and lung expansion. After pneumonectomy, clamps are basically used for drain management to prevent mediastinal shift. It should be noted that postoperative drain management must be performed according to the operative procedure and residual lung condition.