Students' leaving a designated area without permission or supervision is referred to as "elopement," and such behavior clearly presents a unique set of challenges for educational professionals. Elopement is seen in children and youth with a variety of developmental disabilities, including those with intellectual disabilities or autism, as well as those identified with or at risk for emotional and behavioral disorders (EBD). In milder forms, elopement may be simply disruptive and annoying (e.g., students leaving their seats without permission, or students who do not wait, line up, or gather at the appropriate spots when transitioning from one location to another). In more serious forms, students may run, literally leaving their classrooms, school buildings, and even school grounds, which creates potentially serious safety concerns. Elopement often requires teachers to react immediately to prevent students from leaving instructional contexts and entering potentially dangerous situations (e.g., running into traffic, encountering strangers, becoming lost). This may result in teachers leaving other students unsupervised while moving to block or retrieve the eloping student, which ultimately interrupts instruction for all students in the classroom. Despite the risks associated with elopement, there is very little research addressing interventions for treating elopement. Moreover, few investigations have been conducted in school settings. In this article, the authors describe the application of a differential reinforcement procedure in a public elementary school to address the elopement of a 7-year-old male with ASD. This study extends the research on elopement in three ways: (1) all sessions were conducted in a classroom setting; (2) the researchers trained the classroom staff to conduct all sessions; and (3) a prosthetic device, the MotivAider[R] (2005) was used to prompt the classroom teacher to deliver reinforcement. The purpose of this study was to assess the effects of training a special education teacher to implement differential reinforcement procedures to decrease student elopement during a seated instructional activity. The article concludes with some general guidelines for addressing elopement behavior, which the authors believe can be applied effectively and efficiently in classroom contexts for a variety of students with or at risk for EBD. (Contains 1 figure and 1 table.)