Parenting a child with autism has been associated with maternal stress. The present investigation examined children's sleep difficulties and severity of autism along with mothers' sleep problems in relation to stress levels reported by mothers ( N = 72). Mothers' reports of their children's sleep problems were related to mothers' reports of their own sleep difficulties and to the severity of children's autistic symptoms. Severity of autism was predictive of mothers' stress. After controlling for child age and gender, mothers' sleep, and severity of autism, children's sleep was a significant predictor (p less than 0.001) of maternal stress. Findings suggest including children's sleep problems along with their symptomatic behavior when examining factors that contribute to stress in mothers of children with autism. (Contains 4 tables.)