Chronic liver disease and cirrhosis are two of the most important health problems according to current gastroenterology literature. Based on the recent developments in the field of immunology, advanced follow-up and treatment modalities have been introduced for these disorders. Immune defence against viral infections depends on effective cellular immune responses derived mainly from Th1-related cytokines. Th2 type immune responses can inhibit efficient immune function by secretion of several cytokines such as IL-10, TGF-β1. In this particular study, we determined the serum levels of TGF-β1, which plays a role in immune suppression and induction of tissue fibrosis. We evaluated the role of TGF-β1 in the pathogenesis of chronic liver disease and cirrhosis. Fourteen chronic hepatitis B (CHB), 12 chronic hepatitis C (CHC) patients and 21 cirrhotic patients were enrolled in the study. The control group consisted of ten healthy people. Serum TGF-β1 levels were higher in both cirrhosis and CHC group when compared to those in CHB and control groups (P < 0.05). Although serum TGF-β1 levels in the cirrhosis group were higher than that in the CHC group, the difference was not statistically significant. In conclusion, elevated TGF-β1 levels in patients with CHC and cirrhosis may have a role in the pathogenesis and chronicity of these diseases.