In order to assess the frequency and severity of lactic acidosis and 3-hydroxybutyric acidosis in ethanol abusers, 29 patients who presented to an emergency room with acute intoxication were tested. Most were also chronic ethanol abusers but were not otherwise seriously ill. Their serum ethanol concentrations averaged 226.5 +/- 94.8 mg/dl (range 98 to 426 mg/dl). In 20 patients, the plasma lactate level was elevated only mildly or not at all (1.1 to 3.0 mmol/liter). Seven patients had plasma lactate levels between 3.5 and 4.3 mmol/liter, and only two patients had moderately elevated levels, 5.1 and 8.7 mmol/liter. Thus, severe lactic acidosis was uncommon in these ethanol-intoxicated patients. Only two patients had even trivially elevated plasma levels of 3-hydroxybutyrate, 1.0 and 1.2 mmol/liter. Thus, these patients did not have unrecognized "alcoholic ketosis" manifested mainly as 3-hydroxybutyric acidosis. An unexpected and unexplained finding was the presence of hyperchloremia in 10 of the 29 patients, with serum chloride levels of more than 110 mmol/liter.