We have been determining the GGT IE isoenzyme in patients with hepatitis A and B with decomposed liver cirrhosis, with obstructive hepatitis caused by the gall stones. In patients with hepatitis A and B the IE is located between albumin and betaglobulin, as well as in patients with obstructive hepatitis caused by the gall stones; in the latter partly between Alpha 1 and Alpha 2 globulin. In patients with decompensated liver cirrhosis (37.7% of the patients) there was IE activity 100% in Alpha 2 globulin area; in 6.25% of patients the activity was in the prealbumin area. In patients with secondary liver tumors we got a rather high increase of the GGT IE activity in Alpha 1 globulin area, in 77.7% of the patients even 80 to 100%. In some patients with disease progression we noticed the GGT IE activity in Beta globulin area. The results in primary liver malignomas were different. In 68.5% of the patients the GGT IE activity dominated in Alpha 1 globulin area.