The eight classes of procedures studied are positive reinforcement, negative reinforcement, punishment, time-out and response cost, extinction, differential reinforcement, generalization training, and social skills training. Target behaviors are discussed, and some of the undesirable side effects accompanying some behavioral procedures are pointed out. The author argues that those designing and evaluating behavioral programs must be alert to the detection and correction of side effects. Undesirable side effects, such as punishment and aversive control, have been widely recognized. Additionally, positive reinforcement procedures can also produce the undesirable side effects of aggression and reducing performance to a level below that observed before the program was implemented. Critics of behaviorism can be expected to point out the undesirable side effects of reinforcement programs. Therefore, professionals using behavioral strategies in closed institutions for juvenile delinquents and for adult felons must face the issue of undesirable side effects, for it they do not, their critics will. 99 references.