Arteriovenous malformation (AVM) is a vascular abnormality resulting in the development of abnormal connection between an artery and vein without capillary connections. An AVM develops mainly intracranially. Extracranial AVMs are rarely seen. Cheek, ear, nose, auricle, and forehead are the more common sites in the extracranial involvement. They cause cosmetic problems when located in the head and neck region. We report a case of a giant AVM in the floor of the mouth, which has not been specified and has not been reported until now. The lesion, in an elderly man, was supplied by multiple vessels and caused difficulty in speaking and swallowing. The lesion was totally excised after embolization of feeding vessels.