The endobronchial hamartoma is a relatively rare benign tumor of the lung. The symptoms of the endobronchial hamartoma are produced by obstruction of the bronchus and its sequelae. This patient was 51 year old male and complained dypnea, cough and purulent sputum for 2 years. On bronchoscopic view, a yellowish pedunculated mass nearly total occluding right main bronchial lumen was found. Endoscopic biopsy revealed squamous cell metaplasia of the bronchial mucosa. The operation was done with the right pneumonectomy. The pathologic result of the operative specimen was endobronchial hamartoma arisen from the right upper lobe bronchus.