This study reports on the results of a randomized controlled trial that evaluated a caregiverbased intervention program for children with autism in community day-care centers. Thirty-five preschool children with a DSM III-R diagnosis of autism or pervasive developmental disorder were randomized to an experimental or control group. Children in the experimental group were enrolled in day care and their parents and child care workers received a 12-week intervention consisting of lectures and on-site consultations to day-care centers. In addition, supportive work was undertaken with families. Control subjects received day care alone. In the experimental group, there were greater gains in language abilities, significant increases in caregivers' knowledge about autism, greater perception of control on the part of mothers, and greater parent satisfaction. We conclude that this research design demonstrated that the intervention was significantly superior to day care alone.