Renal artery dissections are stenotic or occlusive lesions most often observed in hypertensive patients with underlying atherosclerosis or fibromuscular disease. Acute dissections may present spontaneously, as a complication of diagnostic or therapeutic angiography or as an agonal event associated with overwhelming systemic illness. Chronic dissections may produce renovascular hypertension or be entirely asymptomatic. The lethality of renal artery dissections and the ease and success of revascularization, which preserves renal function and ameliorates associated renovascular hypertension, emphasize the need for an aggressive approach to the recognition and treatment of this entity. Therapy should be directed toward arterial reconstructions and the preservation of functioning renal tissue.