The majority of patients with kidney disease, an estimated 20 million adults in the U.S., will die of cardiovascular disease. Further, the risk for cardiovascular events is 2-3 fold higher than in the general population and increases with the severity of renal impairment [1]. Reasons for this accelerated atherosclerotic process are unclear. Recent evidence suggests that endothelial progenitor cells (EPC) are critical to maintaining vascular integrity [2]. Patient populations with low circulating EPCs, including patients with kidney disease, have excess vascular disease burden. The hematopoietic cytokine, erythropoietin, is a key regulator of EPCs and is reduced in patients with kidney disease [3]. Therefore, we hypothesize that supplementation with the erythropoietin analog, darbepoetin, enhances EPC function leading to improvement in vascular repair mechanisms in patients with chronic (CKD).