OBJECTIVE To compare the efficacy, safety and side effects between subcutaneous and intravenous route of erythropoietin administration in Thai hemodialysis patients. METHODS Retrospective study. METHODS Retrospective study of hemodialysis patients who switched the route of erythropoietin administration from subcutaneous to intravenous in the Renal Unit Department of Medicine, Bangkok Metropolitan Medical College and Vajira Hospital and Thammasat University was carried out. All patients' information was obtained from the medical records. RESULTS 60 patients with stable hematocrit level in the last 3 months of the subcutaneous phase who were switched to intravenous route of erythropoietin administration for at least 6 months were recruited The mean hematocrit level of patients in the last 3 months of the subcutaneous period was 30.49+/-4.21%. After switching to the intravenous route for 6 months, the mean hematocrit level was 30.24+/-4.99%. Two patients had to increase the erythropoietin dosage and no side effects were found in the present study. The mean dosage of erythropoietin administered intravenously was not statistically different from the subcutaneous route. There was no correlation between age, sex, cause of renal failure, transferrin saturation, reticulocyte count, C reactive protein and the dosage of erythropoietin, together with the hematocrit level. No other side effects were encountered during the intravenous phase. CONCLUSIONS This study has shown that the subcutaneous erythropoietin in hemodialysis patients can be changed to the intravenous route in the same dosage with good response and stable hematocrit.