Children presenting with hypertension should be considered for emergency treatment when there is evidence of end-organ toxicity. Complications of extreme hypertension may be very serious, even life threatening, with the potential for life-long sequelae. Of greatest significance is damage to the central nervous system. Treatment of hypertensive emergencies should be directed toward the lowering of blood pressure enough to reduce toxicity, but not at a rate likely to cause hypoperfusion of vital organs. This blood pressure reduction should, in general, be carefully controlled in an intensive care unit, with attention to central nervous system, cardiac, and renal function. Intravenous agents are preferable under these circumstances, due to greater ease in modulating blood pressure. In the absence of specific contraindications, a continuous infusion of nicardipine or sodium nitroprusside is preferable. Intravenous labetalol by bolus injection, followed by continuous infusion, also may be used. Oral agents should be reserved for circumstances in which symptoms of end-organ toxicity are mild or absent. Since general pediatricians have limited experience with the treatment of hypertensive emergencies, consultation with physicians experienced in treating hypertensive emergencies is suggested when possible.