Are psychologists sufficiently knowledgeable about the combinations and patterns of behavioral health conditions among adolescents in the juvenile justice systems? This study reports the findings of information collected through the use of a structured diagnostic interview used in routine evaluations within a state's juvenile justice system. The interview covers 7 conditions in sufficient detail to construct diagnostic algorithms for statistical analyses. Anonymous data from cases involving 519 males and 78 females contained data on major depression, manic episodes, panic attacks, posttraumatic stress disorder, conduct disorder, oppositional defiant disorder, and substance dependence. Results showed that 92% of males met criteria for at least one disorder and 32% met criteria for three or more conditions. For females, the results were 97% and 60%, respectively. The findings suggest that routine assessment of adolescents entering juvenile justice systems should be a universal practice. Failure to identify and treat the conditions present is likely to result in further problems for the adolescents and future costs to society.