Background: The carcinogenesis of hepatocellular carcinoma (HCC) is a multi-factorial, multistep and complex process. Its prognosis is poor and early detection is of the utmost importance. Transforming growth factor β1 (TGF-β1) message RNA (mRNA) has been reported to be elevated in HCC patients using Northern blotting. However, little work has been done about the detection of TGF-β1 mRNA levels in peripheral blood of patients with HCC using the real-time polymerase chain reactions (PCR) method. Objective: To assess the prognostic value of quantitative levels of TGF-β1 mRNA in peripheral blood of patients with HCC, and to investigate the relationship between the expression of TGF-β1 mRNA in peripheral blood and many diagnostic and pathological factors. Methods: We developed an optimized Taqman real-time PCR to quantify TGF-β1 mRNA in peripheral blood of 53 patients with HCC and 44 healthy volunteers. In addition, blood was collected from patients with HCC for measuring levels of total bilirubin (TBil), prealbumin, albumin, alanine aminotransferase (ALT), aspartate aminotransferase (AST), gamma glutamyltranspeptidase (GGT), alpha-L-fucosidase (AFU), alpha fetoprotein (AFP), carcino-embryonic antigen (CEA), carbohydrate antigen 19-9 (CA19-9), viral load and platelet counts. Statistical analysis was performed using the SPSS software system (SPSS 10.0). Results: In real-time PCR, fluorescence was detectable in all blood specimens from patients with HCC and healthy volunteers. The levels of TGF-β1 mRNA expression in patients with HCC were significantly higher compared to that in healthy volunteers (P