This article describes the potential contributions of psychological assessm
ents to the processing of youths in juvenile justice and correctional syste
ms. Standardized psychological assessment instruments and procedures are sh
own to be superior to the informal and unstandardized procedures often empl
oyed in these systems, and they are also shown to lead to more effective de
cisions about youths. Major types of assessments relevant to juvenile justi
ce and correctional systems are reviewed as are models for introducing psyc
hological services into the systems.