We investigated the use of a popular measure, the Children and Adolescent Functional Assessment Scale (CAFAS), in treatment outcome research. The sample included 70 children who had been discharged from an elementary therapeutic classroom (Intensive Mental Health Program). Significant relationships were found between decreases in CAFAS scores and optimal educational placement, contributing to evidence of the scale's discriminant validity. Clinically significant change in CAFAS scores was also investigated, with a 30 point change in score most accurately discriminating between placements after discharge. Further investigations of real world outcomes versus changes in score on this measure are warranted.