Chronic liver disease evaluation is a very complicated process requiring complex assessment of numerous liver functions. In addition to standard methods of investigation we perform biotransformation liver tests for evaluation of microsome enzyme system. Markers of fibrogenesis represent modern noninvasive tests for fibrotic liver process detection in different diseases. The key role in the process of fibrogenesis have the adipose liver cells (ITO cells) producing collagen I, III, IV and lamilin. These cells may be transformed into myofibroblasts-like cells under specific conditions. Kupffer cells and monocytes produce substances stimulating the proliferation and transformation of liver ITO cells as also proteoglycans and hyaluronic acid synthesis. Mediators of this fibrogenetic activity are platelet derived growth factor (PDGF), transforming growth factors alpha and beta, lymphokines and monokines released by T-lymphocytes and macrophages, interleukin 1-alpha and interferon-tau. Acetaldehyde and its metabolites are important stimulators of collagen production by liver fibroblasts. The most often used markers of hepatic fibrogenesis are the following: procollagen III peptide, procollagen IV. type (one of its end carboxypeptide chains is determined-either with 7s collagen or NC1), hyaluronic acid, fibronectin, tenascine and unduline. As the most sensitive markers of fibrinogenesis are considered: hyaluronic acid, laminine, procollagen IV. type. Less often used are enzymes participating in collagen synthesis: prolyl-4-hydroxylase,lysyl-hydroxylase, galactosyl-hydroxylysyl-glucosyl-transferase, monoaminooxidase and N-acetyl-beta-D-glucoseaminidase. Breakdown of collagen is a multienzymatic process, catalysed by collagenases and other proteolytic enzymes. Decreased activity of collagenase is a supporting factor of cirrhosis development. Cirrhosis may be connected also with the levels of inhibitors such as e.g. serum/tissue? inhibitor of metalloproteinase. Biochemical markers of fibrogenesis are useful in regular monitoring of disease development and treatment effectivness and should be an inseparable part of progression assessment in all chronic hepatopathies. (Fig. 3, Ref. 49.)