Hepatocellular carcinoma (HCC) is an environmentally related cancer, with both viral and chemical carcinogens involved in a multistage process. To date, it has been difficult to detect the asymptomatic precursor lesions in early HCC. Therefore, the majority of HCC patients are not amenable to therapy, as they are detected at late stages. To evaluate the significance of tumour necrosis factor-alpha (TNF-alpha), sP-selectin, gamma-glutamyl transferase (GGT), glutathione S-transferase-pi (GST) and alpha-fetoprotein (AFP) in the diagnosis and follow up of HCC patients during chemotherapy with adriamycin, 45 subjects (15 healthy volunteers, 15 with benign liver diseases and 15 HCC patients) are studied before and during chemotherapy (three cycles of intravenous adriamycin). HCC patients had significantly higher serum levels of TNF-alpha, sP-selectin, GGT, GST and AFP Serum levels of GGT and GST were significantly higher in HCC patients with poorly differentiated tumours than in patients with well- and moderately differentiated tumours. Treatment with adriamycin for three cycles produced a significant decrease in TNF-alpha, sP-selectin and GST. Thus, it is concluded that GST is a superior diagnostic indicator and may be a prognostic marker in HCC patients.