The purpose of the present study was to compare DSM-III-R and the proposed DSM-IV 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 prevalence of DSM-III-R diagnoses of alcohol abuse and dependence combined (8.63%) was greater than the corresponding DSM-IV diagnoses (6.00%). Disaggregation of abuse and dependence diagnoses showed that the major discrepancy between the classification systems resided between the abuse categories. Reasons for the discrepancies are discussed in terms of differences in the content of the DSM-III-R and DSM-IV abuse categories, in the relationship that each abuse category shares with its respective dependence category, and the impact of the DSM-III-R duration criterion.