Thymomas are one of the most common neoplasms of the mediastinum derived from thymic epithelium. It is common that invasive thymoma invades the lung, pericardium, and great vessels. Airway compression by mass effect also occurs, but direct polypoid tumor growth into the airway is extremely rare. Only 20 cases of invasive thymoma with endobronchial polypoid growth have previously been reported globally. However, there is no case report of invasive thymoma with endotracheal growth. Herein, we report a rare case of invasive thymoma with endotracheal polypoid growth in a 28-year-old woman.