The purpose of the present study was to experimentally investigate the effects of differential reinforcement of other behavior (DRO) on potential resurgence of a previously reinforced response. During Phase 1, rats’ left lever pressing was reinforced on a fixed-ratio (FR) 20 schedule while extinction was in place for right lever presses. Then, extinction was in effect for all lever presses throughout Phase 2. Phase 3 consisted of an FR 20 schedule for right lever presses while left lever presses were on extinction. Finally, Phase 4 continued the extinction contingency for left lever presses while a 15-second DRO was in effect for right lever presses. The results indicate higher rates of resurgence and more persistent resurgence in this experiment than obtained in previous studies. Characteristics of DRO may have contributed to this effect, including a potential to allow adventitious reinforcement of left lever pressing.