The purpose of this study was to reduce stereotypy and challenging behavior during play skills instruction by adding an abolishing operation component (AOC) to the intervention strategy. An alternating treatments design compared one condition in which participants were allowed to engage in stereotypy freely before beginning the play skills intervention (AOC condition) to a second condition without this free access period (No AOC condition). Across 4 participants with autism spectrum disorders (ASD), levels of stereotypy and challenging behavior were lower and functional play was higher during play intervention sessions that followed the AOC. These data provided support for the inclusion of an AOC in interventions aimed at increasing the play skills of children with ASD who present with stereotypy. (Contains 2 tables and 4 figures.)