In DMS-IV, the diagnosis of alcohol abuse is precluded by the diagnosis of alcohol dependence. The goal of this study was to examine the diagnostic and clinical implications of diagnosing alcohol abuse among alcohol dependent individuals. Treatment-seeking psychiatric outpatients with a lifetime history of alcohol dependence (n=544), some of whom (n=45) did not meet lifetime criteria for alcohol abuse completed in-depth, face-to-face, semi-structured clinical assessments of DSM-IV axis I and axis II psychopathology. Alcohol dependent patients who did not meet criteria for alcohol abuse were significantly more likely to be female, have a later age of onset for alcohol dependence, have fewer dependence symptoms, and have a lower rate of positive family history for alcoholism, and were less likely to report a lifetime history of DSM-IV drug use disorders and PTSD. These findings suggest that diagnosing alcohol abuse among alcohol dependent patients may be clinically useful as an index of severity and higher likelihood of comorbid drug abuse and dependence. Future studies are needed to establish whether these differences are clinically significant in terms of the course of the disorder and response to treatment.