Tissue Polypeptide Antigen (TPA) and alpha 1-fetoprotein (AFP) were determined in sera of 21 patients with hepatocellular carcinomas, in 20 patients with extrahepatic carcinomas and metastases of the liver, as well as in 26 patients with cirrhosis of the liver. TPA was increased (greater than 85 U/L) in all patients with malignant hepatomas, in 80% of patients with metastatic liver cancer and in 35% of patients with cirrhosis of the liver. The critical serum TPA level, above which only malignant liver tumours lay, was statistically evaluated and found to be 187 U/L. All patients with benign liver disease and half of the patients with metastatic liver disease showed TPA values lower than 187 U/L. All of the patients with hepatocellular carcinoma and half of the patients with metastatic liver cancer had TPA values greater than 187 U/L; all of our patients with cirrhosis of the liver, as well as half of the patients with metastatic liver cancer had lower TPA values. 86% out of all hepatoma patients showed increased AFP levels (greater than 9 ng/ml), whereby the AFP concentrations were in the range which is highly suggestive of hepatoma (greater than 174 ng/ml) in 67% of all patients with malignant hepatomas. Patients with metastatic liver cancer and cirrhosis of the liver had AFP levels lower than 174 ng/ml AFP. TPA is an unspecific tumour marker, which can be used together with AFP in the diagnosis of unclear defects in liver parenchyma, in supervision of cirrhosis, as well as in control assessment during chemotherapy or after tumour resection.