Ligands to the benzodiazepine receptor (BZR) accumulate in hepatic encephalopathy; the benzodiazepine antagonist flumazenil can reverse some manifestations of this condition. This study was designed to explore the effects of flumazenil on cognitive function and anxiety levels in cirrhotic patients without hepatic encephalopathy. Twenty such patients--ten alcoholic, ten nonalcoholics--and ten normal volunteers matched for age and sex were randomly allocated to treatment order (flumazenil or placebo first) in a double-blind cross-over trial. Cognitive function was evaluated with a battery of psychological tests shown previously to be sensitive to the impairment induced by liver disease. Cirrhotic patients performed worse than controls on several tests: digit cancellation, digit symbol substitution, key tapping and Reitan's trail B test. Flumazenil did not reverse these cognitive impairments but it did induce anxiety in nonalcoholic cirrhotics. On one index of memory--delayed word recall--alcoholics performed worse than nonalcoholic cirrhotics. Flumazenil reversed this memory impairment in the alcoholic cirrhotic group. These results suggest that alcohol consumption induces changes at the BZR that are different from changes induced solely by liver impairment.