Objective: The objective was to survey the prevalence of parent-reported ADHD diagnosis and to assess its associations with sleep problems among urban school-aged children in China. Method: A random sample of 20,152 school-aged children participated in a cross-sectional survey in eight cities of China. A parent-administered questionnaire and the Children's Sleep Habits Questionnaire were completed to quantify history of ADHD diagnosis and sleep problems, respectively. Results: Slightly more than 4% of Chinese school-aged children were reported to have a history of ADHD diagnosis. The multivariate regression models revealed that, after controlling for some confounders—such as gender, parents' educational level, family income, family structure, and stimulant medication—there was a higher prevalence of sleep problems, especially parasomnias, sleep-disordered breathing, and daytime sleepiness, in children with a history of ADHD diagnosis. Conclusion: The results emphasized the importance of incorporating screens of sleep problems into the evaluation of ADHD.