The Level System is a whole-classroom approach for managing disruptive behavior that utilizes behavioral management strategies such as a token economy, response cost, stimulating rewards, and strategic attention. Using an ABACC' treatment comparison design with follow-up, this study evaluated the effectiveness of the Level System in a preschool classroom compared to (a) strategies already employed by the teacher, and (b) coaching the teacher in the Child-Directed Interaction (CDI) and Parent-Directed Interaction (PDI) phases of Parent-Child Interaction Therapy (PCIT). Teacher- and parent-report measures were administered, and behavioral observation data were collected for child and teacher behavior using videotapes. Results suggested that the amount of inappropriate behavior exhibited by children decreased when the Level System was implemented. Additionally, inappropriate behavior decreased further during the CDI and PDI conditions. (Contains 4 figures.)