RÉSUMÉ
OBJECTIVE: To determine the anatomical variations of the internal jugular vein [IJV] in Pakistani adult population with the help of Site Rite II ultrasound machine. MATERIAL AND METHOD: The right IJV relation to the carotid artery was visualized at four different landmarks [angle of the mandible, thyroid cartilage, cricoid cartilage, and the supraclavicular area]. Size of IJV in comparison to carotid artery was also seen. In 49 cases the IJV was found in aberrant relation to carotid artery at the angle of the mandible [p value < 0.05], 22 at the thyroid cartilage, 20 at the cricoid cartilage, and 46 at the supraclavicular area [p value < 0.05]. In 93% of cases the IJV was found to be larger than the carotid artery. Care should be taken while cannulating IJV at the angle of the mandible and supra clavicular area by external landmark guided technique. Ultrasound guided technique should be used in every anticipated difficult case