Classrooms are dynamic environments in which teachers and students engage in ongoing reciprocal interactions throughout the school day. Classes that include classwide effective intervention practices are likely to have positive teacher-student interactions and to promote student learning and engagement while minimizing problem behaviors. However, when classwide interventions are missing from a classroom, teacher-student interactions are likely to become reactively negative (and perhaps even coercive). Such interactions interfere with learning and create a chaotic and aversive classroom atmosphere. Classwide interventions are a group of research-based effective teaching strategies used positively and preventively to promote and reinforce social and behavioral competence in students while minimizing problem behaviors. Classwide interventions do not represent a single type of intervention; instead, they include a combination of effective behavior management practices, such as using contingent and frequent "praise," providing "opportunities to respond" (OTRs), and applying "classroom rules." This article discusses some classwide interventions which teachers should consider when implementing positive behavior supports. These are: (1) Using close supervision and monitoring; (2) Establishing and teaching classroom rules; (3) Increasing OTRs; (4) Increasing contingent praise; (5) Providing feedback and error correction and monitoring progress; and (6) Implementing the good behavior game (GBG). (Contains 1 table.)