Since its introduction, recombinant human erythropoietin (rHuEPO) has become the standard of care for renal anemia. Because of its relatively short half-life, however, it generally is administered two to three times per week. Darbepoetin alfa (novel erythropoiesis stimulating protein [NESP]) is a longer acting erythropoietic agent that allows less frequent dosing to treat anemia. Decreased dosing frequency should result in enhanced patient compliance and convenience and minimize the burden of frequent administration on staff. NESP is biochemically distinct from rHuEPO, having five N-linked carbohydrate chains (two more than rHuEPO). In animal studies, NESP had a half-life approximately three times longer than rHuEPO and raised hemoglobin effectively when administered less frequently than rHuEPO. NESP has been evaluated in clinical trials of dialysis and chronic kidney disease patients. Pharmacokinetic data confirmed that patients with anemia required less frequent dosing with NESP than rHuEPO. After intravenous administration, the mean elimination half-life of NESP was 25.3 hours versus 8.5 hours for rHuEPO. In patients who are rHuEPO-naive and in patients previously managed with rHuEPO, NESP is as effective as rHuEPO for maintaining hemoglobin concentration when administered intravenously or subcutaneously at a reduced frequency of once weekly or once every other week. NESP is well tolerated and has a safety profile comparable to that of rHuEPO. There have been no reports of antibody formation associated with NESP. NESP is an important new tool for physicians to use in the treatment of anemia of chronic kidney disease.