For many years, differential reinforcement has been a prevalent and preferred treatment procedure for the reduction of behavior disorders. This paper reviews the procedural variations of differential reinforcement and discusses their functional properties. It is proposed that such procedures are more likely to be successful if behavioral function is a primary consideration in prescribing treatments; furthermore, limited success noted in previous research may be due to the arbitrary relationship that often exists between reinforcers and target behaviors when behavioral function is unknown. Despite the promise of a function-based approach to differential reinforcement, several current limitations exist in the identification and manipulation of relevant variables. Thus, further research is required to elucidate the relationship between aberrant behaviors and the variables responsible for maintaining them; otherwise, successful treatment cannot be expected. Several areas for future research are discussed conceptually as extensions of current and past experimentation.