A study of 21 consecutive autopsy specimens of infants less than one year of age and weighing less than 6 kilograms was performed to determine the topographic anatomy and regional relationships of the central venous anatomy. This anatomy was compared with 14 additional autopsies performed upon older children. There was no significant difference in diameter between the internal jugular and subclavian venous system, on either the right or left side. In the infant, the right and left subclavian veins entered the central system at an acute angle. The left innominate vein joined the right innominate vein at a right angle. These angulations become less acute after one year of age. This adult configuration may account for the relative ease of central venous cannulation through the percutaneous subclavian approach in the older patient. In contrast, the external and internal jugular veins entered centrally in almost a straight line even in the infant. The findings of this study suggest that the internal and external jugular veins should be considered as safe and reliable portals for percutaneous entry into the central venous system in infants. In the infant less than one year of age, the difficult patient (for example, those with thrombocytopenia or severe pulmonary failure) or when the surgeon is less familiar with the infraclavicular approach, the veins of the neck may, in fact, be the site of choice. Additionally, we believe that a surgeon should not hesitate to switch to the internal or external jugular site after unsuccessful attempts at percutaneous entry into the subclavian vein.