The current study examined sleep problems and pre-sleep arousal among 52 anxious children and adolescents, aged 7–14 years, in relation to age, sex, ethnicity, and primary anxiety disorder. Assessment included structured diagnostic interviews and parent and child completed measures of sleep problems and pre-sleep arousal. Overall, 85% of parents reported clinically-significant child sleep problems, whereas 54% of youth reported trouble sleeping. Young children, those with primary generalized anxiety disorder, and Latino youth experienced the greatest levels of sleep disturbance. Additionally, greater levels of pre-sleep cognitive rather than somatic arousal were found and pre-sleep thoughts were associated with decreased total sleep duration and greater sleep problems. Findings suggest that attention to sleep should be part of assessment procedures for anxious children in both research and clinical settings.