From leading authorities, this state-of-the-art manual presents the Early Start Denver Model (ESDM), the first comprehensive, empirically tested intervention specifically designed for toddlers and preschoolers with autism. Supported by the principles of developmental psychology and applied behavior analysis, ESDM's intensive teaching interventions are delivered within play-based, relationship-focused routines. The manual provides structured, hands-on strategies for working with very young children in individual and group settings to promote development in such key domains as imitation; communication; social, cognitive, and motor skills; adaptive behavior; and play. Contents include: (1) Current Understanding of Infant Learning and Autism; (2) An Overview of the Early Start Denver Model; (3) Using the Early Start Denver Model; (4) Developing Short-Term Learning Objectives; (5) Formulating Daily Teaching Targets and Tracking Progress; (6) Developing Plans and Frames for Teaching; (7) Developing Imitation and Play; (8) Developing Nonverbal Communication; (9) Developing Verbal Communication; and (10) Using the Early Start Denver Model in Group Setting. Appended are: (1) Early Start Denver Model Curriculum Checklist and Item Descriptions; and (2) Early Start Denver Model Teaching Fidelity Rating System: Administration and Coding.