The present study provided an overview of the Couinaud’s segmentation system of the portal and hepatic veins, the controversies surrounding it and the typical variations the anatomy of the portal and hepatic veins. Even with the advent of three-dimensional CT (3DCT), it goes without saying that a basic knowledge of Couinaud’s classification is essential. Future advances in technology are expected to enable the superimposition of preoperative 3D images and intraoperative real-time ultrasound images. Looking forward, a secure knowledge of the fundamentals of liver anatomy is necessary for patient safety during liver transplantation or R0 resection, in which the tumour is not exposed. (Kimura in Kan Tan Sui Gazo 13: 355-363, 2011
