It has been shown that an increase in prolidase enzyme activity is correlated with increased rates of collagen turnover. In previous studies, it has been investigated that whether prolidase activity may be an index of liver fibrosis, but the results are controversial. Therefore, the aim of this study was to investigate serum prolidase activity in patients with biopsy-proven chronic viral hepatitis (CVH) and to find out whether prolidase enzyme activity is correlated with histopathological findings in those CVH patients.  Fifty-four patients with CVH and 44 healthy controls were enrolled. Serum prolidase enzyme activity was measured spectrophotometrically. Serum prolidase activity was significantly higher in CVH than controls (p<0.001). A significant correlation was observed between serum prolidase activity and fibrosis score in patients with CVH (r=0.525, p<0.05). Our findings indicated that prolidase activity seems to be correlated with the level of fibrosis. Thus, serum prolidase activity may be an adjunctive tool in predicting the degree and stage of liver histopathological findings.