The present study investigated the effectiveness of an intervention comprising posted classroom rules, token economy, response cost, and mystery motivators in reducing disruptive classroom behavior. Participants were three male second grade students identified as having oppositional defiant disorder. To serve as an additional control, a class composite was formed using five male classmates whose behavior was judged appropriate. The study employed a multiple baseline across subjects design. Results showed an immediate and pronounced decrease in disruptive behaviors for all three students. Furthermore, their rates of disruptive behaviors were consistently below that of the class composite control. This decrease in inappropriate classroom behavior continued during follow-up. The teacher reported that the intervention was relatively easy to implement, and together with its effectiveness in reducing disruptive behaviors, functioned to reinforce her willingness to incorporate the intervention into daily instructional practice.