The aim is to make head and neck surgeons aware of a rare variation in the course of Spinal accessory nerve in relation to Internal carotid artery at higher level of neck dissection, thus minimizing anatomical surprises during neck dissection. Maxillofacial Surgeons often have to perform neck dissection to manage metastatic nodal diseases as in head and neck cancer and it is very important identifying and preserving the good and essentials while removing the pathological ones to the highest precision. Anatomy is the road map to perform a successful surgery. Knowing the variations of neck structures is important as the ignorance of the anatomical variations may lead to iatrogenic injury to vital structures during surgery thus leading to treatment failure. In this article we present a rare variation of SAN crossing ventral to the Internal Carotid Artery, found during a Supraomohyoid Neck Dissection (SOHND) of left side as a part of surgery along with Hemiglossectomy for a Squamous cell carcinoma (SCC) of left tongue. Knowledge of the rare variation of Spinal accessory nerve in neck in rerlation to its adjacent structures is important, as the major nerves and vessels play important roles as landmarks during head neck surgery. Iatrogenic injury to vital structures like Spinal Accessory Nerve (SAN) during neck dissection at Level IIb may lead to morbidity as shoulder syndrome though oncological clearance of this level of lymph nodes is of utmost importance. The SAN is considered as the landmark of the anteroinferior border of Level IIb and may cross the Internal Jugular Vein (IJV) dorsally, ventrally or through the vein. So it is important to know the variations of Spinal accessory nerve in relation to major blood vessels of neck to avoid any anatomical surprises during surgery.