The Department of Veterans Affairs is the largest provider of drug dependence treatment services in the United States. However, a national evaluation of primarily drug-dependent veterans has never been reported. Findings from the Drug Abuse Treatment Services Evaluation Project, a three-year investigation of drug dependence treatment within the Department of Veterans Affairs, are discussed. Demographic and diagnostic data are presented for the population of 46,047 inpatients discharged with drug dependence diagnoses in Fiscal Year 1991. Patient subtypes and clinical issues of growing relevance to the treatment of drug-dependent veterans are discussed.