Parents of children with autism spectrum disorder (ASD) often encounter unique challenges when attempting to understand their children’s challenging behaviors such as self-injury, aggression, noncompliance, and stereotypies. In this study, we aimed to analyze and clarify the definition of challenging behaviors in individuals with ASD, identify the variables associated with challenging behaviors, and determine the function of these behaviors. Systematic observation and data collection are crucial to understand the functions of specific behaviors exhibited by individuals with ASD based on their antecedents and consequences. Knowledge regarding these will enable clinicians to develop and implement effective interventions. Additionally, the treatment approach should aim for generalization to improve the quality of lives of both children with ASD and their caregivers.