Recombinant human erythropoietins (rhEPO) reliably increase hemoglobin levels in cancer patients experiencing chemotherapy-associated anemia. However, in patients with "anemia of cancer" not being treated with chemotherapy, rhEPO appears less effective. Recently, two studies have been broadly discussed which have raised concern on the concomitant use of erythropoietin and chemo- or radiation therapy in cancer patients. In addition, use of rhEPO is generally not considered cost-effective. Thus, the application of rhEPO should be limited to indications with proven clinical benefit. This review will provide an overview of the state of the art use of rhEPO in anemic patients and will discuss future developments.