The authors present oblique sections of the retroperitoneum adapted to the morphology of each patient, which affects both the liver and the organisation of the retroperitoneum. This original method involve two incidences for studying the left and right retroperitoneum separately with vertical sectional planes. The authors postulate that the orientation of the retroperitoneal viscera depends on the degree of hepatic development, so these incidences are chosen with reference to axial sections of the portal bifurcation and the middle hepatic v.: the two vascular landmarks of the liver. Anatomic and radiologic studies confirm the reliability of these landmarks and their easy application in modern imaging. Such new data improve our understanding of the classical topographic anatomy of the retroperitoneum. These oblique sections promote the radiologic study of the portal and systemic vessels, renal pedicles, suprarenal glands and pancreas.