Hepatocellular carcinoma (HCC) is one of the most frequent malignant tumors in clinics. It is quite necessary and important to explore new approaches for early prognosis of HCC. The present study aimed to study the immunological and biochemical characterization of an epithelial membrane antigen associated with HCC. Serum samples from HCC patients (n=80) undergoing surgery and 20 serum samples from healthy individuals served as normal controls were used. The target epithelial membrane antigen (EMA) was purified from sera of HCC patients using electroelution technique and has been characterized. The purified EMA was characterized to be glycoprotein with molecular weight 130 kDa. Also, EMA was quantified in serum samples of 80 patients that were histopathologically proven to have HCC using ELISA. There was a highly significant difference between the value of EMA in HCC patients (8.9 ± 6.8 μg/ml) and that of normal individuals (1.6 ± 1.0 μg/ml) at (P < 0.0001). Accordingly, the estimation of serum EMA can be considered as a prognostic test for HCC.