Resurgence occurs when a previously extinguished behavior reemerges once a more recently reinforced behavior is placed on extinction. Previous research has suggested that nontargeted responses within the same response class recur alongside target-response resurgence (e.g., da Silva, Maxwell, & Lattal, 2008;Lieving, Hagopian, Long, & O'Connor, 2004). The purpose of this two-experiment investigation was to examine target response resurgence while simultaneously measuring the occurrence of nontargeted responses. Three children diagnosed with autism spectrum disorder who displayed multiple topographies of problem behavior participated. In Experiment 1, a three-phase resurgence procedure was conducted and all three participants displayed target-response resurgence accompanied by the emergence of nontargeted forms of problem behavior. These findings were replicated in Experiment 2 using a 30-min assessment procedure. The implications of these findings as they pertain to the treatment of severe problem behavior and utility of a brief relapse assessment are discussed.