Ultrasound-guided catheterization of the central vein is a precise, safe, and easy compared with the conventional landmark method. We incidentally detected thrombosis in the right internal jugular vein (IJV) during the ultrasound-guided cannulation (on) in a 22-month-old male patient. Cardiac operations had been performed 5 times previously and the right IJV was cannulated lastly 2 months ago. The thrombosis occluded right IJV near totally, so we cannulated the left IJV instead using the ultrasound. This case demonstrates that ultrasound-guided central vein catheterization approach is helpful not only in precise puncture but also in selection of appropriate vessel.