It is well documented that children with autism spectrum disorders (ASD) benefit from early intensive behavioral intervention (EIBI). The majority of programs for toddlers with ASD have been conducted in children's homes. Although there are some benefits to working in homes, there are a number of drawbacks such as isolation, cost, and lack of appropriate social and communicative models. The purpose of this presentation is describe the current state of knowledge about early intervention for children with ASD, including the results of two recently completed randomized clinical trials on school-based services. Implications of these results will be discussed as they apply to the basic dimensions of applied behavior analysis.