A 66-year-old woman was referred to this institution for treatment of hemoptysis, atelectasis of the left upper lobe, and marked hypoxia necessitating oxygen therapy. A low anterior resection of the rectum had been performed for rectal adenocarcinoma 6 years and 3 months before this admission, and was followed by another resection after a local recurrence 20 months later. Bronchoscopy revealed an endobronchial tumor obstructing the left upper lobe bronchus. Tissue from a transbronchial biopsy revealed metastatic rectal carcinoma of the endobronchial lumen. There was no evidence of local recurrence or metastasis to other organs. A left pneumonectomy and lymph node dissection were performed successfully. The postoperative course was uneventful, and the patient was discharged after marked improvement of the arterial blood gas results. The pathological diagnosis of a resected tissue specimen was metastatic adenocarcinoma of the left hilar lymph nodes with invasion of the left main bronchus and protrusion into the endobronchial lumen. The patient remained disease-free for 6 months. At that time, computed tomography of the chest disclosed small metastases in the right lung and chemotherapy was begun.