Hypertension is a major risk factor for myocardial infarction, stroke, and cardiovascular mortality in adults; its treatment reduces the risk of cardiovascular events. In recent times, attention is being paid to monitoring of blood pressure from childhood to adulthood. Childhood hypertension is associated with hypertension in later life, and early intervention is important. In the Korean socioeconomic background, a rapid increase is observed in the number of obesity cases and the rate of increase in the incidence of obesity is more in childhood. The strong association of high blood pressure with obesity and the marked increase in the incidence of childhood obesity indicate that both hypertension and prehypertension are becoming significant health issues. In this comprehensive review, we acquaint the clinician with the available literature on childhood hypertension to provide recommendations for the diagnosis, evaluation, and treatment of hypertension based on the available evidence and consensus in Korean clinical conditions.