Severe hypertension, also called as hypertensive crisis, is uncommon in children. Such crises are potentially life-threatening, and call for immediate medical attention to prevent or limit end-organ damage. Hypertension in children is classified based on age, gender and height percentiles according to the guidelines provided by the Indian Society of Pediatric Nephrology, which are in broad conformity with the Fourth US Task Force Report on Hypertension in children. Traditionally, hypertensive crises are further classified as hypertensive emergencies and hypertensive urgencies. While the former term is reserved for severe hypertension associated with life-threatening symptoms and/or target-organ injury, the term ‘urgencies’ refers to hypertension with less significant symptoms and no target-organ injury. Hence, hypertensive emergencies include encephalopathy, cardiac failure, retinal hemorrhage and renal dysfunction, while severe hypertension in the absence of clinical or laboratory evidence of end-organ damage is referred as hypertensive urgency. The implication of urgency is that if left untreated, it may progress to an emergency. However, the distinction is not absolute, and is based on clinical judgement.