Post-tonsillectomy hemorrhage is a relatively common complication but life-threatening bleedings are rare. In this paper, we present a case who had undergone tonsillectomy with bipolar diathermy in an another hospital and who was referred to our clinic following a massive hemorrhage from the tonsil bed on the 27th postoperative day. Upon determining that the bleeding was caused by the necrosis of the internal carotid artery, the ligation of the internal carotid artery was performed.