AbstractSimultaneous determination of serum levels of specific γ‐glutamyltransferase isoenzyme II (GGTII) and alkaline phosphatase isoenzyme I (ALPI), α1‐antitrypsin (αAT) and α‐fetoprotein (AFP) was carried out in 101 patients with primary liver cancer (PLC), 60 with liver cirrhosis, 66 with chronic hepatitis, 14 with benign space occupying lesion of the liver and 100 normal subjects. The positivity rates for GGTII, ALPI, α1AT and AFP in patients with PLC were 85.1%, 24.8%, 75.1% and 76.2% respectively; significantly higher than those in the other patients and normal subjects. In the PLC group, the positivity rates for combined determination of AFP and GGTII or α1AT were 93.1% and 92.1% respectively, significantly higher than single determination of AFP. The results of simultaneous determination of GGTII, ALPI, α1AT and AFP in the area of PLC patients showed that the sensitivity of at least one positive marker was as high as 98% and the specificity of at least two positive markers was 94.3%. Of PLC patients with AFP ≤ 50 ng/ml; ≤ 200 ng/ml and ≤ 400 ng/ml, 91.7%, 93.8% and 90.5% respectively, were diagnosed with combined determination of GGTII, ALPI and α1AT. Thus, simultaneous determination of GGTII, ALPI, α1AT and AFP is useful in the diagnosis of PLC, especially PLC with negative AFP or sl