Hepatocellular carcinoma (HCC) is an environmentally related cancer, with both viral and chemical carcinogens involved in multistage process. Up now, it is difficult to detect the asymptomatic precursor lesions in early stages of HCC. Therefore, the majority of HCC patients are not amenable to curative therapy as they are detected at late stages. To evaluate the significance of TNF-α, sP-selectin, GGT, GSTPi and AFP in the diagnosis and follow up of HCC patients during chemotherapy with adriamycin, 45 subjects were studied (15 healthy volunteers as control group, 15 with benign liver diseases (SHF), and 15 HCC patients before and during chemotherapy (3 cycles of intravenous adriamycin). HCC patients had significantly higher serum level of TNF-α, sP-selectin, GGT, GST-Pi and AFP. Serum levels of GGT and GST-Pi were significantly higher in HCC patients with poorly differentiated tumors than in patients with well and moderately differentiated tumors. Treatment with adriamycin for three cycles forced a significant decrease in TNF-α, sP-selectin and GST-Pi. We conclude that GST-Pi is superior as a diagnostic and may be a prognostic marker in HCC patients. [Turk J Cancer 2005;35(1):5-11]