Hypertension is a major risk factor of atherosclerosis which results in cardiovascular disease, and remains a major health problem worldwide. While children are more likely to have secondary hypertension, recent studies support the theory that the prevalence of essential hypertension in children and adolescents is increasing with the global epidemic of childhood obesity, and close attention is needed. Evaluation of hypertension in the pediatric age group should be guided by the age at presentation, and renal diseases must be considered in every child with hypertension, because of the prevalence of renovascular and renal parenchymal disorders as the etiology in any age group. The majority of children with chronic kidney disease are hypertensive, and many have associated end organ damage. Thus, once hypertension has been confirmed, end organ care as well as pharmacologic therapy must be continued. In renovascular hypertension, as cure could be gained with surgical/endovascular intervention, accurate diagnosis is important and it is recommended that every suspected child should undergo angiography.