Pulmonary pneumatocele that forms immediately after pulmonary resection is extremely rare. This report describes a case of pneumatocele that formed rapidly in the left lower lobe immediately after left upper lobectomy in a patient with lung cancer and emphysema. Massive and persistent air leakage through a chest tube was noted immediately after chest closure. Therefore, the chest was reopened, and the cyst wall was incised. The air leakage point was cauterized and covered with a polyglycolic acid sheet and fibrin glue. Herein, we report a rare case of newly developed pneumatocele immediately after lobectomy.