SUMMAR Y The objectives of the study were to describe the prevalence, odds, and predictors of 36 paediatric sleep behaviours and describe their coexistence in a school-age normal population. The design was community-based questionnaire survey of sleep-wake patterns, sleep environment, and 36 sleep behaviours indicative of six sleep disordersubscales using the Health-Behaviour Questionnaire. A caregiversÕ report of 3045 children aged 6-13 years in Belgium constituted the participants. Prevalence of each sleep behaviour was calculated. Log-linear modelling within and between the sleep disorder-subscales was used to screen for coexistence. The effect size of selected nighttime parameters to the likelihood of sleep behaviours and disorder-subscale was expressed as odds ratios via logit regression analysis. Significant differences in sleepwake patterns were found between weekday and weekend. Ranking by odds showed that: (1) sleep problems such as Ôtired when waking upÕ, Õrepetitive limb movementsÕ, Ôgoing to bed reluctantlyÕ, and Ôsleep paralysisÕ and; (2) the disorder-subscale Ôexcessive somnolenceÕ are common in children. Coexistences within and between disordersubscales of sleep problems are evident in a school-age, normal population. These results suggest that disorders of excessive somnolence (DES) are highly prevalent in a non-clinical sample of school-age children. Furthermore, sleep-onset latency and a noisy, not well-darkened room are predictive towards the odds for exhibiting sleep problems and disorders. It is advocated that more information on the importance of good sleep-wake hygiene should reach parents and children.