Pilot randomized controlled trial of a Functional Behavior Skills Training program for young children with Autism Spectrum Disorder who have significant early learning skill impairments and their families

•Developed Functional Behavior Skills Training program for children with ASD.•Parent training component provided support and helped promote children's skills.•Functional Behavior Skills Training reduced problem behaviors in children.•Functional skills training enhanced children's performance of targeted skills.•Parent training improved parents’ knowledge but not strain or sense of competence.