This report focuses on a potentially fatal hemorrhage arising from dental implant placement in the mandible. Anatomic considerations of the lingual artery and its divisions in the floor of the mouth are discussed. In addition, various methods of controlling bleeding from the floor of the mouth are reviewed. The case presented is unusual in that intraoral ligation of the transected vessel was possible despite the presence of massive sublingual, submental, and submandibular hematomas as well as severely distorted anatomy. This case represents a severe complication resulting from a seemingly minor oral surgical procedure. Those performing endosteal implant placement should be knowledgeable in the management of such complications.