This dose-finding, placebo-controlled study evaluated the safety and efficacy of darbepoetin alfa administered every 3 weeks (Q3W) to anaemic patients receiving chemotherapy. In part A, patients (haemoglobin </=110 g/l) were randomised in a 1:4 ratio to receive 1 of 6 doses of darbepoetin alfa (4.5, 6.75, 9.0, 12.0, 13.5 and 15.0 microg/kg) or placebo Q3W for 12 weeks. In part B, patients received open-label darbepoetin alfa. Patients (n=249) were evaluated for safety, haemoglobin endpoints and red blood cell (RBC) transfusions. Darbepoetin alfa given at doses ranging from 4.5 to 15.0 microg/kg Q3W was well tolerated and comparable to placebo in terms of safety. No neutralising antibodies were detected. All doses (from 4.5 to 15 microg/kg) reduced transfusions compared with placebo, and resulted in >50% of patients achieving a haematopoietic response. Administration of darbepoetin alfa Q3W has a tolerable safety profile and effectively ameliorates anaemia due to chemotherapy.