Sleep is essential, but poses a risk to breathing in some children. We have outlined the developmental changes in sleep patterns and physiology, and the evidence of deleterious effects of sleep deprivation and of sleep-related breathing disorder (SRBD). Some factors increase the risk of adenotonsillar surgery and should be excluded before contemplating surgery in a secondary care setting. Screening for SRBD is indicated in some conditions, which are discussed. Although simple studies may suffice for many patients, there are a few who need more detailed assessment with polysomnography. A managed clinical network would be the most appropriate model to ensure appropriate organisation and utilisation of scarce resources in this area.