Abstract Several important physiological and maturational changes occur in sleep development during the paediatric age range, particularly during infancy and in early childhood. As the pathology of sleep apnoea is superimposed onto a developing and often plastic physiological system, children often show a different pathophysiology to their adult counterparts. These factors need to be incorporated into the evaluation of a child’s sleep problems. Particular attention should be paid to the developmental stage of the child. Investigation, interpretation and subsequent management provide further unique challenges and during successive reviews predicted normal changes must also be taken into account. This review article discusses the important physiological and maturational changes that occur in sleep during childhood, some common paediatric sleep conditions and their presentation and the appropriate evaluation and management of these conditions. In the course of the discussion, we have stressed important differences between paediatric and adult sleep medicine.