The Nisonger Child Behavior Rating Form (NCBRF) has been used in several large studies of risperidone in children with low IQs (36–84) and disruptive behavior disorders (conduct disorder and oppositional defiant disorder). We wanted to develop a companion instrument for assessing ‘typically developing’ children and adolescents. In this study, we modified the NCBRF and obtained parent ratings on 485 typically developing children attending regular classes. We also obtained parent ratings on 46 children with conduct disorder and oppositional defiant disorder. Factor analyses of the ratings produced a single Positive Social subscale (10 items) and six Problem Behavior subscales (54 items): (i) Conduct Problems, (ii) Oppositional, (iii) Hyperactive, (iv) Inattentive, (v) Withdrawn/Dysphoric, and (vi) Overly Sensitive. Comparison of the school and disruptive behavior disorder groups showed large and significant differences, providing evidence of criterion validity for the Conduct Problem and Oppositional subscales, and on a Disruptive Total composite. Analysis for age and sex effects showed no main effects and no interaction of age and sex. Norms were presented. The factor structure of problem behavior tends to differ in significant ways between typically developing children and children having developmental disabilities. Like its predecessor, the NCBRF-TIQ (for typical IQ) is in the public domain and is available free to researchers and clinicians for assessment and treatment.