Ethanol metabolism and its influence on serum lactate/pyruvate ratio was studied after intravenous infusion of ethanol in 17 patients: 4 controls, 5 alcoholics with cirrhosis, 4 non-alcoholic cirrhotics and 4 alcoholics without liver disease. All refrained from the use of alcohol and drugs 4 weeks prior to the experiment. After maximal ethanol blood levels were achieved at the end of the infusion, ethanol removal occurred at two different rates. This was probably due to the fact that different volumes of ethanol were distributed with time: a fast period (30 to 60 min) and a slow period (60 to 180 min). The rates of disappearence in the two periods were similar in all groups which suggests that liver cirrhosis, independent of clinical severity and/or chronic alcoholism with previous abstinence from alcohol, does not modify ethanol metabolic rates in the liver. The relation lactate/pyruvate doubled in all cases but it occurred within 30 minutes in the groups without liver disease and within 60 minutes in the cirrhotics. This could account for the decreased liability of cirrhotic patients to alcohol hypoglycemia.