This paper reviews evidence of the success of behavior intervention approaches which teach students with challenging behaviors alternative functional communication behaviors. Research supporting the view that challenging behavior is a form of nonverbal communication is reviewed, noting the importance of identifying what such individuals are "saying" with their behavior problems. Functional communication training is described as providing the consequences originally maintaining the target behavior with a new more appropriate behavior. Specific interventions which used functional communication to reduce such behavior problems as aggression, self-injurious behavior, and stereotyped or self-stimulatory behaviors are reviewed. Factors affecting the initial effectiveness of functional communication training include matching responses to functions of the challenging behavior and ensuring that the appropriate behavior is more response efficient than the inappropriate behavior. Factors affecting generalizability and maintenance include response acceptability, recognizability of the communicative response, and communicative context. Recommendations for implementation stress home-school collaboration, teamwork, and development of secondary prevention strategies. Other recommendations address development of a comprehensive model of behavior, development of assessment procedures, improved use of augmentative communication strategies, and primary prevention of serious behavior problems. (Contains 73 references or suggested resources.) (DB)