The Early Social Interaction Project (ESI) is a multisite toddler treatment study in the FSU Autism Institute funded by the US Department of Education, Autism Speaks, and the National Institute of Mental Health. ESI provides early intervention for toddlers with autism spectrum disorders (ASD) and their families. ESI teaches parents how to support their child’s social communication, emotional regulatoin, and play in everyday activities and settings. Dr. Amy Wetherby and Dr. Catherine Lord, Director of the Institute of Brain Development in New York, are Co-Principal Investigators of an ongoing 6-year randomized clinical trial of the effectiveness of teaching parents of 100 toddlers with ASD how to support social communication, emotional regulation, and play in everyday activities beginning at 18 months of age using the ESI model. The findings of this study will provide important evidence of the effectiveness of a community-based intervention implemented by parents of toddlers with ASD and will substantiate the importance of autism screening for toddlers so families can access early intervention. ESI is part of the Toddler Treatment Network, a consortium of 8 research sites sponsored by Autism Speaks.