Advanced cancer is often accompanied by anaemia, which may worsen with concomitant administration of chemotherapy. Serum erythropoietin (EPO) concentrations are lower in cancer patients than in patients with iron deficiency, suggesting that the anaemia observed in cancer patients is at least partially due to a relative deficiency of EPO. Consequently, we studied the effects of recombinant human erythropoietin (r-HuEPO) therapy in three populations of anaemic cancer patients: patients not receiving concomitant chemotherapy or radiotherapy; patients receiving cyclic, non-cisplatin-containing chemotherapy, and patients receiving cyclic cisplatin-containing chemotherapy. Therapy with r-HuEPO was well tolerated; it increased haematocrit levels and corrected anaemia, irrespective of concomitant chemotherapy or the type of chemotherapy administered. A dose of 150 U/kg r-HuEPO given subcutaneously 3 times weekly decreased transfusion requirements after the 1st month of therapy; improved functional capacity was noted in patients who achieved a significant increase in haematocrit in response to r-HuEPO therapy.