We diagnosed and classified a diverse sample of 133 narcotic addicts using DSM-III criteria. Seventy-seven percent of the sample met criteria for one or more diagnoses on axis I, and 65% met criteria for a personality disorder on axis II. In total, 93% met the criteria for one or more psychiatric disorders other than substance abuse. Although heterogeneity of diagnosis is noted, depressions and personality disorders, often in combination, were most prominent. Several factors related to specific diagnostic groupings are analyzed and their significance for the psychopathology of narcotic addiction is discussed.