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 disorder-subscales using the Health-Behaviour Questionnaire. A caregivers' 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 night-time parameters to the likelihood of sleep behaviours and disorder-subscale was expressed as odds ratios via logit regression analysis. Significant differences in sleep-wake patterns were found between weekday and weekend. Ranking by odds showed that: (1) sleep problems such as 'tired when waking up', 'repetitive limb movements', 'going to bed reluctantly', and 'sleep paralysis' and; (2) the disorder-subscale 'excessive somnolence' are common in children. Coexistences within and between disorder-subscales 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.