DSM IV includes three clusters of items that are used to establish diagnoses for the Disruptive Behavior Disorders: Attention Deficit, Conduct, and Oppositional Defiant. In this report, we examine the feasibility of using the items in each cluster to form a rating scale. We studied eighty-four consecutive school-aged referrals to an inner-city child and adolescent Psychiatry clinic. Case diagnosis was established with a clinician's KID-SCID assessment. Parents and teachers rated the 41 DSM items on four-point scales, and completed the Conners' Rating Scales, in English or Spanish. In this paper we report psychometrics of the new scale, the Rating Scale for Disruptive Behavior Disorders (RS-DBD), along with the agreement among parents and teachers, and concurrence between the new scales and the relevant Conners' scales. While, the parent and teacher ratings may provide a useful index for severity of behavioral disturbance in the home and school environments, it will not establish a diagnosis. There was a great deal of comorbidity among diagnostic groups.