The MACI seeks to separate symptoms, such as depression, violent behavior, or anxiety from personality trends that an adolescent may experience in their relating to the outside world. The Personality Pattern scales are not intended to diagnose personality disorders in adolescence but to provide a description of the strategies the youth is currently using to obtain need gratification. This study used the MACI to examine personality typologies within a sample of male adolescent offenders. The relationship between offense histories and racial group membership with personality cluster membership were also examined. A Ward’s method cluster analysis yielded a four-cluster solution, and each cluster was provided a clinically relevant label. These clusters were labeled as: (1) disruptive, antisocials; (2) agreeable, antisocials; (3) anxious, prosocials; and (4) reactive, depressives. The results of the cluster analysis indicate a higher number of youth classified in Clusters 3 and 4 as compared to the membership sizes of the other clusters. Clusters 3 and 4 appeared to be the internalizing subgroups of the sample and made up 70 percent of the sample. The findings point toward a heterogeneity of symptoms in this delinquent sample beyond that of the typical conduct disorder and oppositional defiant disorder syndromes of behavior. It appears that youths with relatively similar problematic behaviors will respond to psychological instruments in a wide variety of manners. The results lend support for the increased use of theoretically based instruments in psychotherapy and assessment with youthful offenders for the purpose of treatment planning, placement, and recommendations. 3 tables, 24 references