Although cardiovascular disease (CVD) generally manifests in adulthood, the development of cardiovascular pathology is known to start in early life. Higher mean blood pressure (BP) is an established risk factor for CVD. The magnitude of association for BP measured in adolescence/early adulthood with CVD incidence and mortality is the same as the association for BP measured in mid-life or older adulthood, with evidence from prospective cohort studies, RCTs and Mendelian Randomization highlighting the importance of cumulative risk with longer duration of high BP, and the importance of early life interventions to prevent age-related increases. Studies in adults have also demonstrated that greater within-individual variability of BP over a 24-hour period is a risk factor for CVD independently of mean level. BP ‘dipping’ is the degree to which BP is lower during the night compared with the daytime; lower dipping is also associated with CVD risk independent of mean BP level. Much less is known about BP variability and BP dipping within children and adolescents, with the available evidence coming from a small number of studies from the USA.