We experienced 4 cases of postoperative perforation in the bronchus intermedius membrane (PBIM) after primary lung cancer resection. Three patients had undergone a right lower lobectomy and 1 patient had undergone a right upper lobectomy; as part of a systemic lymph node dissection, the subcarinal lymph node (Station 7) was dissected in all cases. Leakages were detected on postoperative days 3, 10, 11, and 26, respectively. The clinical signs of PBIM included the appearance of sputum like pleural effusion, decreased oxygenation, elevated inflammatory markers, pneumothorax, and infected pleural effusion. PBIM was confirmed by bronchofiberscopy. Direct suturing of the perforated membrane, followed by rapping with an omental flap was performed in 1 case; completion bilobectomies, followed by rapping of the bronchial stump with an omental flap or an intercostal muscle flap were performed in 2 cases; and a completion pneumonectomy, followed by rapping of the bronchial stump with an omental flap was performed in 1 case. All 4 of the cases were successfully treated.