Purpose: To describe the anatomy of the lingual perimandibular vessels and emphasize the distance to the bone. Materials and Methods: The hemifacial lower third was dissected in 12 human cadavers. The blood vessels in the floor of the mouth were exposed using sagittal incisions at the canine, mental foramen, and second molar areas. Results: The diameter of the dissected vessels ranged from 0.5 to 3 mm (mean, 1.5 mm). Most vessels were found superior to the mylohyoid muscle in the canine area and beneath the muscle in the mental and second molar areas. The smallest median vertical distance from blood vessel to bone was in the canine area (14.5 mm), followed by the mental foramen area (15.5 mm) and the second premolar area (19 mm). The median horizontal distance of the vessels from the lingual plate was 2 mm at the canine and second molar areas and 4 mm at the mental area. Discussion: Lingual plate perforation, especially anterior to the canine area, can easily injure blood vessels in the floor of the mouth and cause life-threatening hemorrhage following implant placement. Bleeding can occur when the mandibular lingual plate is perforated. Care should be taken to recognize situations where this complication may occur. Conclusions: Based on the study of human cadavers, it appears that vessels in the floor of the mouth are sometimes in close proximity to the site of implant placement. Caution should be exercised when placing implants in this area. (Basic Science) Keywords: dental implants, lingual perimandibular vessels, sublingual artery, submental artery