There is increasing evidence that meaningful subgroups of alcoholics may exist. Cloninger et al. and von Knorring et al. have developed criteria to delineate what both call type 1 and type 2 alcoholism. However, when we compared their criteria in a predominantly inpatient sample of male alcoholics, we found large differences between the approaches in identifying type 1 and type 2 alcoholism. Concordance was equally low in a subsample of 34 alcoholics exhibiting antisocial behavior and when subjects were divided by whether the first alcohol-related problem began before or after 20 years of age. Similar findings emerged when we limited our analyses to primary alcoholics and alcoholics with no other mental disorders.