Ths use of Canter's (1976) Assertive Discipline program as a schoolwide response to classroom problems is gaining nationwide support. The program is designed to provide educators with the competence and confidence necessary to assert their influence and deal effectively with discipline problems. The purpose of this article is to discuss the program and review the limited research assessing its effectiveness. Although the Assertive Discipline training program has been presented to over 400,000 educators throughout the United States since its introduction, only 11 research projects have examined it. The single study in which there was experimental manipulation of classroom control methods to determine positive and negative effects of the program found a classwide reduction of two problematic student behaviors: out-of-seat behavior and inappropriate talking among third-grade students. Other research based on surveys shows a positive relationship between the program and (1) reduction in time devoted to discipline referrals; (2) improvement in classroom discipline and student behavior; and (3) improvement of teachers' and students' self-concept. A second empirical study conducted in 36 Oregon third-grade classrooms observed that classrooms using Assertive Discipline exhibited lower levels of off-task behavior than did classrooms not using the program. (RH)