We report a case of massive engorgement of an asymptomatic tongue hemangioma with the use of a supraglottic airway device (SGA) during general anesthesia for transurethral resection of a tumor on the lateral wall of the urinary bladder. This was probably a result of obstruction of the venous drainage of the hemangioma due to the pressure exerted by the inflated cuff of the SGA. The SGA was removed and the trachea was intubated and the engorgement resolved completely in a few hours.