We report a rare case of pulmonary metastasis of invasive thymoma, with endobronchial polypoid growth causing hemosputum in a 77-year-old man. The patient had been admitted 8 years earlier for the treatment of invasive thymoma and had undergone extended thymo-thymectomy through a mid-sternotomy, followed by a course of radiotherapy. Pulmonary metastases developed 3 years after surgery, for which the patient received several courses of chemotherapy; however, the tumor continued to progress gradually. He presented at our emergency unit within 4 years of completion of the chemotherapy, with sudden massive hemoptysis. We performed endotracheal intubation to prevent suffocation and bronchoscopic examination revealed that a tumor and blood clots had obstructed the left main bronchus. We performed bronchial arterial embolization and endoscopic electrosurgery to resect the tumor, then occluded the responsible bronchus with an endobronchial Watanabe spigot to prevent further endobronchial polypoid growth and bronchial hemorrhage from the invasive thymoma.