The authors investigated the intrahepatic lymphatic vessels of the human liver under a light and electron microscope. The histological material was obtained from 10 patients operated on account of simple cholecystolithiasis. The beginnings of the lymphatic capillaries are in the periphery of the perilobular connective tissue of the portobiliary space in the vicinity of openings of Mall's space. Communication between lymphatic capillaries and Mall's space was not proved. The fine structure of the openings in Mall's space with numerous microvilli of hepatocytes pointing towards the perilobular connective tissue were described. Mall's space communicates and is interconnected in a multiple way with intercellular spaces between neighbouring hepatocytes. Here also the plasmalemma of hepatocytes forms a system of microvilli which form the borderline of the interhepatocytic space. The ultrastructure of both systems of spaces corresponds to the pattern on the hepatocyte surface in Disse's perisinusoid space. The cell population of hepatocytes holds a special position because it lacks the lamina basalis as a selective barrier against the connective tissue interstitium. This structural specificity indicates the extensive and rapid transport of lymph via the perisinusoid Disse spaces into the blood stream of the hepatic sinusoids, also lacking lamina basalis. Mall's space and the system of interhepatocytic spaces form a continuous system which is in close but not direct contact with the incipient intrahepatic lymphatic capillaries.