Renal vein occlusion in adults is usually a result of vein thrombosis, which is frequently associated with the nephrotic syndrome. The anatomy of renal vascularization is of primary importance for understanding its pathophysiological responses and the clinical and diagnostic presentation of patients with this condition. The reaction of the kidney to its vein occlusion is determined by the balance between the acuteness of the disease, extent of the development of collateral circulation, involvement of one or both kidneys and the origin of the underlying disease. Renal vein occlusion is generally a complication of some other condition, but may also occur as a primary event. The main goals of therapy should be to conserve renal parenchyma in order to maintain renal function and prevent thromboembolic phenomena.