Background/Aims: Darbepoetin alpha is effective for renal anemia when epoetin is insufficient. We previously reported that the dose conversion ratio from epoetin alpha to darbepoetin alpha was 1:350.5 after 24 weeks of follow-up. This study assessed the conversion ratio in stable Japanese hemodialysis patients after 52 weeks. Methods: A total of 104 hemodialysis patients who were stable on intravenous epoetin alpha were switched to intravenous darbepoetin alpha according to the 1:200 rule. Then they were followed for 52 weeks to assess changes of hemoglobin and the darbepoetin alpha dose. Results: Eighty-five patients completed the study. Their hemoglobin increased very rapidly during the first 8 weeks. The final conversion ratio was 1:286.6 at 52 weeks. Darbepoetin alpha showed similar efficacy in diabetics and non-diabetics. Patients switching from a high epoetin alpha dose (=4500 IU/week) had a higher conversion ratio compared with those switching from a low dose (<4500 IU/week). Conclusions: The dose conversion ratio of 1:200 was unsuitable and led to a rapid increase of hemoglobin. A conversion ratio of 1:250 to 1:300 should be employed when switching from epoetin alpha to darbepoetin alpha in Japanese patients.