This study examined reinforcement of compliance with positive (''do'') and negative ("don't") commands, along with its effects on inappropriate behavior in children. The design of the study was A-B· A-C-B-C counterbalanced across two subjects. In both subjects, reinforcement of compliance to .. do" commands resulted in increased compliance to this type of command. Similarly, reinforcement of compliance with "don't" commands resulted in increased compliance to "don't" commands. In addition, a tendency for compliance with the reinforced type of command to generalize to the nonreinforced type was observed in some phases. Response covariation was.also observed in some phases. Response covariation was also observed in some phases between compliance with both types of commands and inappropriate behavior. Additionally, there was a tendency for the number of "don't" commands to increase. in frequency concurrent with increased compliance to ''don't" commands. Probable causes for this effect and concern about the reinforcement of "don't"commands are discussed.