Along with behavioral deficits (e.g. communication, social skills), individuals with autism spectrum disorder (ASD) often present with various behavioral excesses, which may inhibit their ability to be successful in a school, home, or community environment. We refer to behavioral excesses as “challenging behaviors” because they challenge the person’s ability to achieve success (Olive, Boutot, & Tarvox, 2011). Examples of behavioral excesses, or challenging behaviors that may be seen in students with autism are stereotypical/self-stimulatory behaviors (such as hand flapping or making loud noises), self-injurious behaviors (such as head hitting or self biting), aggression (i.e. pinching, kicking), eloping (running away), noncompliance, work refusal, off task, and out of seat, among others. A key factor associated with challenging behaviors is often the level of communication the individual has, as well as the degree of structure and behavioral training of the adults working with him or her. The purpose of this chapter is to discuss some of the major considerations when addressing challenging behaviors of students with ASD. We will begin with a rationale behind identification of the function of the behavior, because function-based decision making is the first step in identifying and resolving the behavior. Next, we will list and describe some antecedent-based strategies that can be used to create necessary structure and prevent challenging behaviors. We will complete the chapter with a discussion of consequence-based strategies, paying particular attention to the difference between reinforcement and punishment and the guidelines for the use of each of these.