The present study examines the association between breath alcohol concentration (BAC) at arrest and problem drinking for a sample of 1,283 male DWI offenders in the US Army. The results indicated a moderate but statistically significant association between BAC at arrest and DSM-III diagnosis. BAC's ability to indicate problem drinking was also compared with the diagnostic ability of three well-known, paper-and-pencil instruments designed for that purpose. BAC performed as well in identifying problems with alcohol as did the MAST, the MacAndrew Scale of the MMPI, and the Vaillant.