This study compared self-regulation and external regulation procedures in the treatment of children's disruptive classroom behavior. Following the collection of baseline data, three of the four most disruptive children in each of 10 first and second grade classrooms were reinforced by the experimenter for achieving low rates of disruptive behavior. The fourth child served as a control subject throughout the experiment. Two of the three experimental subjects were then taught to self-observe their own disruptive behavior. In the final reinforcement period, these subjects were given control over dispensing reinforcers to themselves, based on their self-collected behavioral data while subjects in the other experimental group continued with the externally managed reinforcement. In extinction, reinforcement was discontinued for all subjects, but one of the self-regulation subjects in each classroom continued to overtly self-observe. Results indicated that both reinforcement programs produced a considerable reduction in disruptive behavior. The self-regulation procedures were slightly more effective in reducing disruptiveness than was the external regulation procedure and this advantage persisted into extinction. These results suggest that self-regulation procedures provide a practical, inexpensive, and powerful alternative in dealing with disruptive behavior in children. (Author)