Background Central venous catheters are often required in emergency rooms and intensive care and/or those undergoing major surgical procedures. In this study, we aimed to gain a better understanding of the anatomy of the femoral vessel in relation to central venous cannulation. Methods The right and left (total of 180) femoral veins (FVs) of 90 consecutive pediatric patients were retrospectively evaluated using computed tomography images. Patients were divided into two groups according to their age: group 1, patients up to 9 years of age; and group 2, patients between 9 and 16 years of age. Results The position and overlap of femoral artery (FA) to FV are significantly different between the left and right sides in both groups (P = 0.001). The left FV was most commonly located medial to the FA. However, the right FV was most commonly located posterior-medial to the FA. The incidence of overlap of the FA over the FV was significantly lower at the left side in both groups. Conclusion The incidence of overlap of the FA over the FV was significantly lower at the left side in pediatric patients. This finding was similar between the patients aged 2-8 years and those aged 9-16 years and may have significant clinical implications. Guiding clinicians to select the left FV of children for cannulation may result in lower arterial puncture rates while accessing the central vein. © 2013 Blackwell Publishing Ltd.