Obstructive sleep apnoea (OSA) is a very common disease with a prevalence that ranges from 1% to 6% in children. It is characterized by intermittent partial or complete occlusion of the upper airway during sleep, leading to recurrent arousals and disturbed sleep architecture, to neurocognitive disorders and alterations in homeostatic gas exchange. Cardiovascular complications may develop in children with OSA through various mechanisms including activation and dysregulation of the sympathetic nervous system, induction of pro-inflammatory and pro-oxidant status and increased risk of systemic hypertension. As the deleterious effects of OSA on the cardio-vascular system may start early in life, in this brief review we focused our attention both on early and late cardiological changes induced by apnoeic events in the paediatric population, by reviewing recent findings in the literature.