Studies of behavior modification interventions for disruptive behavior in schools have generally focused on classroom behavior with less research directed toward child behavior in other school settings (e.g., cafeterias). The present report documents the effect of a group contingency intervention with a random reward component, targeting disruptive cafeteria behavior. An uncontrolled study of the effect of the group contingency program across the school year suggested substantial behavior improvement after the program started. Two natural treatment discontinuations during the same school year provide further support for the intervention. Both sources of information suggest behavioral improvement in rule-following behavior when the program was actively implemented. (Contains 1 figure.)