Sleep problems are common in children with autism spectrum disorder (ASD) and adversely impact daytime functioning. Although no questionnaires have been developed to assess sleep in children with ASD, the 33-item Children's Sleep Habits Questionnaire (CSHQ) is widely used in this population. We examined the factor structure of the CSHQ in 2872 children (age 4-10 years) enrolled in the Autism Treatment Network. A four-factor solution (Sleep Initiation and Duration, Sleep Anxiety/Co-Sleeping, Night Waking/Parasomnias, and Daytime Alertness) with 5-6 items per factor explained 75% of the total variation. Ten items failed to load on any factor. This abbreviated 23-item four-factor version of this measure may be useful when assessing sleep in children with ASD.