Profuse intraoperative hemorrhage is an uncommon complication of tonsillectomy. We present a three-year-old girl who underwent a routine adenotonsillectomy during which massive bleeding occurred from a large vessel in the right tonsillar fossae. Angiography revealed an aberrant right lingual artery with a pseudoaneurysm. The right lingual artery was embolized with multiple coils and the bleeding was halted. The causes and treatment of extracranial carotid artery pseudoaneurysms are discussed.