This study provided sleep education to parents of children with autism spectrum disorder (ASD) to determine whether an individual or group format was more effective in improving sleep and aspects of daytime behavior and family functioning. Eighty children, ages 2-10 years, with ASD and sleep onset delay completed the study. Actigraphy and parent questionnaires were collected at baseline and 1 month after treatment. Mode of education did not affect outcomes. Sleep latency, insomnia subscales on the Children's Sleep Habits Questionnaire, and other outcomes related to child and family functioning improved with treatment. Parent-based sleep education, delivered in relatively few sessions, was associated with improved sleep onset delay in children with ASD. Group versus individualized education did not affect outcome.