Serum tissue polypeptide antigen (TPA) was determined in 86 cirrhotic patients who underwent a thorough clinical and laboratory evaluation. Increased serum TPA levels were found in 87.2% of the patients (81% of Child’s A, 81.3% of Child’s B and 97% of Child’s C) with very high levels in some cases. There were significant correlations between TPA and several clinical and biochemical tests, especially AST (r = 0.678, p < 0.000001), and this enzyme was the best predictor of TPA levels. Patients with abnormal AST had also significantly higher serum levels of TPA than those with normal AST in each of the Child’s class (p < 0.01 for each). TPA values were found to be more frequently abnormal than AST ones in cirrhotics (p = 0.009) and could be used as indirect markers of activity in these patients. The underlying mechanism involved in the increase in TPA in cirrhosis was probably related to the cytolytic/regenerative activity of the liver. TPA cannot be used as a tumor marker in these p