In this study, a multiple baseline design across three young children with autism was used to assess the impact of individualized behavior support, implemented through family-school collaboration, on the children's appropriate and problem behaviors and adult-child interactions. A positive behavior support process was used to promote family-school collaboration and to design the individualized intervention. Data indicated that the children's target behaviors improved with the intervention during circle time at school and play time at home, and their behaviors generalized to nontargeted center time at school and play at the community playground. Teacher and mother positive interactions with the children increased while negative interactions decreased. Social validity indicated that the interventions provided through family-school collaboration were acceptable and effective. (Contains 4 figures.)