A traditional method for internal jugular vein catheterization has been through the transjugular approach. These days, ultrasound-guided cannulation is the preferred mode because of the higher success and lower complication rates. Complications associated with the transjugular approach include neck hematoma caused by carotid artery puncture, pleural puncture leading to pneumothorax and air embolism. Thoracic duct injury is a rare complication of left internal jugular vein catheterization. This complication occurred in one of the patients in whom ultrasound-guided left internal jugular vein catheterization was used. The anatomical basis of this injury is discussed here.