The purpose of the present study was to compare DSM-III-R and the proposed DSM-IV (options 1 and 2) diagnostic criteria for alcohol abuse and dependence in a representative sample of the United States general population. Alcohol abuse and dependence diagnostic categories were contrasted in terms of prevalence and overlap. The prevalences of DSM-III-R and DSM-IV diagnoses of alcohol abuse and dependence combined were remarkably similar. However, disaggregation of abuse and dependence diagnoses showed that there were major discrepancies between the classification systems. Reasons for these discrepancies are discussed in terms of differences in the number of diagnostic criteria and the content of the DSM-III-R and DSM-IV abuse and dependence categories, the requirement for physiological dependence in DSM-IV classifications, the relationship between the abuse and dependence categories, and the impact of the duration criteria.