Total GGT and GGT complexed with low-density-lipoprotein plus very low-density lipoprotein (LDL + VLDL) have been evaluated in sera from 53 healthy subjects, 23 patients with chronic hepatitis, 87 with liver cirrhosis and 50 with liver tumors (primary and metastatic). A cut-off of 20 U/l of GGT complexed with LDL + VLDL results in a diagnostic sensitivity of 84% for liver tumor patients, and a diagnostic specificity of about 80% towards the two groups of patients affected by cirrhosis or chronic hepatitis. This test, because of its high diagnostic efficiency, is a useful addition to the battery of laboratory tests that serve to discriminate cirrhosis and chronic hepatitis from liver malignancies.