Although there is extensive literature describing the characteristics of individuals entering treatment for alcoholism, few research reports are available describing the personality characteristics of individuals addicted to cocaine. Forty-four matched patient pairs, one member of each pair who abused cocaine and the other alcohol, were compared on the basis of their Minnesota Multiphasic Personality Inventory (MMPI) profiles. The subjects were matched on the basis of age, sex, and race from a larger population entering an inpatient addiction treatment center. Statistical analysis revealed more similarities than differences between the two groups, with the average profile type for both cocaine and alcohol abusers being 4-2. These results are discussed in the context of previous reports of psychopathology among cocaine abusers and personality theories of drug choice. The number of different code types within each substance abuse group is also reported and the concept of profile heterogeneity supported. Profile subtypes among cocaine patients are described clinically along with their implications for treatment.