Abstract
The lingual vessels and its branches being superficial at under surface of tongue and floor if mouth may get injured during surgery over of floor of mouth.In two cases, lingual vessels were severed accdentally during surgery with excessive haemorrhage. This study was done to care the lingual vessels during surgery. Four main surgical dangerzone are found and emphasis is being given to be over cautious while operating over this surgical danger zones.Surgery over the floor of mouth is done in a number of conditions. Lingual vessels being very superficial, its sub-lingual branches are damaged during surgery if surgeon is not cautious and may create problems.To avoid this, thorough knowledge of correct surgical anatomy, course & relation of lingual vessels and floor of mouth is essential.