Antecedent interventions are a class of intervention strategies in which environmental stimuli are manipulated prior to a behavior occurring, with the intention of stopping a behavior before it occurs. Antecedent interventions may also be used to modify settings such that students may no longer recognize triggers for problem behaviors. The chapter describes various advantages to antecedent interventions in relation to other classes of intervention strategies. Next, considerations for implementing antecedent interventions are discussed, including developing a comprehensive plan and ongoing data collection. The chapter then presents a range of antecedent interventions. Developing clear expectations, use of classroom seating arrangements, praise, increasing structure, delivery of effective instructions, and modifying task difficulty are among the procedures highlighted in the chapter.