Abstract To investigate possible effects of withdrawal on carbohydrate metabolism in chronic alcoholic patients, intravenous glucose tolerance tests were performed in three periods in 11 alcoholic patients: early abstinence (less than three days), early abstinence plus ethanol (1 g/kg/BW IV), and late abstinence (three weeks later). According to liver biopsy results and laboratory tests, patients were classified as a group with liver damage (four cases) and a group without it (seven cases). In the group without damage, glucose tolerance expressed as K% and compared to a control group, was significantly decreased in early and late abstinence but not after the infusion of ethanol. Cases with damage also had glucose intolerance at admission. Plasma insulin levels after the glucose load were significantly lower at ten and 30 minutes in the group without damage, in early or late abstinence. They were normal in the presence of ethanol. Patients with liver damage presented higher basal and postglucose plasma insulin concentrations. It was concluded that glucose intolerance in alcoholic patients is a common finding that occurs in the presence or absence of liver damage. In cases with liver damage it seems to be due to peripheral insulin resistance. In those without damage it is related to low peripherovenous insulin levels.