Plasma 1,2-propanediol, D,L,-2,3-butanediol and 2,3-meso-butanediol were measured in 29 patients with biopsy proven alcoholic cirrhosis and 10 control subjects, none of whom had measurable blood alcohol levels. None of these compounds were present in control subjects at level above 5 nmol/ml. Seventeen (59%) of 29 serum samples drawn from patients with alcoholic cirrhosis contained 1,2-propanediol in concentrations above 5 nmol/ml (range less than 5.0 nmol/ml-35.4 nmol/ml, median 5.6), 8 (28%) of 29 samples contained D,L-2,3-butanediol in concentrations above 5.0 nmol/ml (range less than 5.0 nmol/ml-211 nmol/ml) and 7 (25%) of 29 samples contained meso-2,3-butanediol in concentrations above 5.0 nmol/ml (range less than 5.0-63.4 nmol/ml). In alcohol abstinent patients with alcoholic cirrhosis elevated serum 2,3-butanediol is due neither to ingestion of diols from undistilled alcoholic beverages nor is it likely to arise directly from the metabolic products of ethanol. In future studies on the origin of 2,3-butanediol in alcoholic patients biopsy evidence of the degree of associated liver damage should be obtained.