Hepatocellular carcinoma is one of the most common malignancies worldwide. Invasiveness of this tumour seems to be related to degradation of extracellular matrix. Such proteolytic enzymes as: cathepsin B and L, plasmin, collagenase and trypsin are thought to play a pivotal role in this process. Enzymatic activity depends on balance between enzymes and their inhibitors and--moreover--on interactions among these enzymes. The purpose of our study was to evaluate enzymatic activity of cathepsin B, cathepsin B and L, plasmin, collagenase and trypsin in patients with hepatocellular carcinoma in liver tissue and in peripheral blood. Then correlations between activity of enzymes (mentioned above) and clinical status, pathological findings and laboratory tests were assessed. Our study was conducted on 14 patients who underwent surgery because of hepatocellular carcinoma. Tissue samples were obtained during surgery from neoplastic area and from non-neoplastic area. Peripheral blood was withdrawn before surgery and within early post-operative period. Proteolytic activity of these enzymes was determined with use of fluorometric assay. Enzymatic activity in tissue samples was referred to protein concentration (BCA assay) and to DNA concentration (fluorometric assay). RESULTS Proteolytic activity of plasmin and trypsin in neoplastic tissue were significantly lower as compared to non-neoplastic area of these patients (p = 0.0356; p = 0.0412, respectively). Activity of the remaining enzymes: cathepsin B, cathepsin B and L and collagenase did not differ significantly. No difference was demonstrated between activity of enzymes in peripheral blood withdrawn before surgery and in postoperative period. There was a statistically significant inverse correlation between serum AFP level and enzymatic activity of cathepsin B, cathepsin B and L and collagenase in tumor tissue. Lower activity of all investigated enzymes was observed in tumor tissue of HBV related hepatocellular carcinoma in comparison with the remaining tissue samples. Correlation between patients age and activity of enzymes was not statistically significant. CONCLUSIONS Although the evaluation of presented enzymatic profile did not allow for the assessment of associations between investigated enzymes, our results demonstrated correlations between proteolytic activity of enzymes and serum AFP level, viral status, but it requires further investigations.