All 1,312 male inmates in the initial pool completed the MMPI, MCMI, Wide Range Achievement Test (WRAT), and a Substance Abuse Level Checklist as part of their evaluation. Of this group, 20 percent committed crimes against persons, 43 percent committed property crimes, 12 percent drug related offenses, 7 percent indecent liberties, and 3 percent rape. Those felons with scores at Level 3 or higher on the SAL were selected for the K-Means Clusters Analysis program. Five groups were identified. Cluster 1 (N=362) was a mix of the psychopathic deviate and narcisstic personality and reported drug and alcohol abuse. Cluster 2 (N=127) revealed the most disturbed group with characteristics of depression, paranoia, psychasthenia, and schizophrenia on the MMPI and schizoid, avoidant, dependent, and passive aggressive as well as anxious, alcohol and drug abuser, and dysthymic. Cluster 3 (N=321) appeared to be the streetwise, manipulative, low anxiety individual found in the drug culture. Cluster 4 (N=376) had no elevations on any scales except the typical elevation on MMPI 4. Cluster 5 was the chronic depression anxious individual. Similarities between these findings and those with non-inmate samples of substance abusers are described. 2 tables, 22 references, and 1 footnote