This study aimed primarily to compare the parent-reported sleep of children with ICD-10 hyperkinetic disorder (HKD) versus community children. Thirty children aged 5-13 years (83.3% boys) diagnosed with HKD by their child and adolescent psychiatrists took part in this study, plus 30 community children, matched for sex, age, and school year. Compared to the controls, the HKD children showed significantly later bedtimes, stronger bedtime resistance, longer sleep latency, shorter sleep; more frequent behaviors and symptoms concerning falling asleep into parents bed, needing something special to initiate sleep, nightmares, sleep talking, sleep bruxism, fear from darkness, bedwetting, and, most notably, loud snoring (26.7%); they also tended to show higher daytime somnolence. Attention deficit/hyperactivity disorder (ADHD)/HKD children may thus have more sleep-related problems than typically developing children. Alternatively, our results may reflect misdiagnoses; thus, special attention should be directed to comorbidity and differential diagnosis issues between sleep disturbances and ADHD/HKD.