Hypertensive crises constitute a group of distinct clinico-pathological entities in which rapid control of hypertension is indicated to previous serious complications. Although systemic blood pressure is invariably elevated in these conditions, it is the status of the target organ function which determines the need for urgent reduction of blood pressure. The physicians should be cognizant of the pathophysiological basis of hypertensive crises so that rational therapeutic choices can be made. The chief objective should be to arrest and, if possible, to reverse the target organ damage. Once the diagnosis of hypertensive crisis is evident, the blood pressure should be lowered quickly while paying careful attention to the cardiovascular, neurologic, and renal function. Several potent, parentally effective antihypertensive drugs such as nitroprusside, labetalol, and nicardipine are available to produce an immediate fall in blood pressure. The choice of drug therapy should be made on the basis of the pharmacodynamic and clinical effects, advantages, and disadvantages. Once the emergency situation is resolved, the etiology of hypertensive crisis should be considered.