Internal jugular vein (IJV) catheterization is frequently performed in infants undergoing major surgery. Although it has been suggested that head rotation increases the degree of overlapping between IJV and carotid artery (CA), IJV catheterization without head rotation is extremely difficult in infants. The aim of the present study is to evaluate whether the caudo-lateral traction of the ipsilateral arm can decrease the degree of overlapping between IJV and CA in infants during head rotation.