Internal jugular veins (IJV) are commonly used to obtain central venous access. However percutaneous cannulation of the IJVis difficult in infants and young children because of its diminutive size. The aim of this study was to evaluate the effect of skin traction on the cross-sectional area of the IJV in anaesthetised infants (younger than one year) and young children (one to six years) using ultrasound. Sixty-seven subjects undergoing general anaesthesia were studied. The cross-sectional area of the IJV was measured at the junction of the two heads of the sternocleidomastoid using ultrasound. Skin traction was performed by stretching the skin over the puncture point with pieces of surgical tape in both cephalad and caudad directions. The measurements were made after the induction of anaesthesia with patients in the supine position and with positive pressure ventilation. Skin traction increased the maximum cross-sectional area of the IJV by 39.9 +/- 29.6% in infants and by 33.8 +/- 21.9% in children (P < 0.01). This increase might facilitate easier and safer IJV cannulation in infants and children.