Protein S (PS), protein C (PC), and antithrombin (AT) are produced by the liver, and their levels were previously shown to be reduced in chronic as well as acute liver disease. The aim of this study was to determine whether measurement of PS, PC, and AT levels in patients would be as good as the commonly used clinical and histological parameters of liver disease in discriminating early and advanced hepatocyte dysfunction. A total of 154 patients were recruited and categorized into five groups: hepatitis B inactive carriers in group 1 (n = 29), nonalcoholic steatohepatitis patients in group 2 (n = 30), chronic hepatitis B patients with elevated liver enzymes in group 3 (n = 29), chronic hepatitis C patients with elevated liver enzymes in group 4 (n = 30), liver cirrhosis patients in group 5 (n = 36). There were significant differences between groups in the levels of PC (P = 0.0001), total PS (P = 0.0001), and free PS (P = 0.0001) and AT (P = 0.0001). These parameters were least affected in the control group, then groups 1 and 2, followed by groups 3 and 4, and most affected in group 5. No differences in these tests were detected between groups 1 and 2 and between groups 3 and 4. Univariate and multivariate analyses showed that free PS was the only predictor of significant inflammation (P = 0.0001), and AT (P = 0.001) and PC (P = 0.003) were the most important factors associated with advanced fibrosis. Both PS and PC are sensitive markers of liver disease, but PS is a sensitive marker of liver inflammation, whereas PC may be a more sensitive marker for liver fibrosis.