Isolated spontaneous renal artery dissection is a rare condition that can result in renal parenchymal loss and severe hypertension. Although several risk factors have been identified in association with renal artery dissection, the natural history is not well defined. The rarity and nonspecific presentation of the disease often lead to diagnostic delay. That, coupled with the anatomic limitations imposed by dissection into small branch arteries, frequently precludes successful revascularization. Over a 12-month period, four cases of spontaneous renal artery dissection (SRAD) were treated at a single institution. The patients (ages 44-58 years) presented with acute onset of abdominal/flank pain, fever, and hematuria. Diagnostic work-up included an abdominal CT scan revealing segmental renal infarction. Angiographic evaluation was diagnostic for renal artery dissection in all cases. In one case there was evidence of fibromuscular dysplasia (FMD), and in a second there was acute dissection superimposed upon atherosclerotic disease. Diagnosis was made within 12-72 hr of the onset of symptoms. All patients were managed expectantly with anticoagulation. Two patients were known to have a history of hypertension prior to admission. All four patients have required antihypertensive treatment following dissection, but the condition has been easily controlled. Renal function has remained stable in all cases. None of the four cases required exploration. Two of the four patients underwent repeat angiographic evaluation for recurrent symptoms of pain. In the case of the patient with FMD, a new dissection was seen in the contralateral renal artery, and in the second, repeat angiogram revealed proximal remodeling of the dissected artery. Management strategies for SRAD include surgical revascularization, endovascular intervention, and observation with or without anticoagulation. The available literature does not demonstrate a clear benefit of treatment with any of these modalities. In the short term, the combination of anticoagulation and expectant management appears to produce satisfactory outcomes for this difficult problem.