In a group of 205 patients with alcoholic diseases of liver the diagnostic relevance of biochemical tests (GOT, GPT, AP, GGTP, BSP) was reconsidered with discriminatory process (separation of diagnosis). The group contained 16 patients with nutritional-caused and 41 cases with alcoholic-caused fatty-infiltration of liver. 148 patients showed a toxic chronic liver disease; 52 a chronic hepatitis and 96 cirrhosis of liver. Laparoscopy and morphology guaranteed the clinical diagnosis and therefore the accuracy of biochemistry in separation of diagnosis was given. The biochemical tests were not able to offer a separation of fatty-infiltration with reference to cause, changes of the process in toxic hepatitis and cirrhosis were announced. Intersection in several cases was noticed and biochemical tests were not able to substitute endoscopy and morphology for clinical and diagnostic use in all cases. In every regard the enzyme-tests,--above mentioned--, and determination of sulfobromthalein are aptly to development of diseases and deficiency of alcohol.