Evaluated the construct validity of the MCBC scales and behavior profiles by determining the relationship between the MCBC and the clinical findings and recommendations that resulted from an interdisciplinary evaluation of children (N = 217) referred to a clinic for developmental disabilities. There were few differences in MCBC scale means and percentage occurrences of behavior profiles as a function of demographic factors and broad diagnostic categories. Substantial association was found between the MCBC and clinical findings of behavior problems. The association of the MCBC and clinical findings suggestive of affective problems was not as substantial, which suggests a need to augment the sensitivity of the MCBC in this area. The findings also suggested both the potential and the need for evolving additional MCBC behavior profiles that would reflect additional clinically meaningful subgroups among developmentally disabled children.