OBJECTIVES: To estimate the probability that epoetin alfa is more cost-effective than darbepoetin alfa for the treatment of chemotherapy related anemia in Sweden using a cost-effectiveness simulation model. METHODS: Studies for recommended dosing regimens of epoetin alfa and darbepoetin alfa were identified from the literature and used to assess haematopoietic response rates, dose escalation rates and the mean number of RBC transfusions required in chemotherapy patients. A simulation model including estimates of proportions, means and variances of these outcomes was established to estimate costs and effectiveness of these agents over 12 weeks. Published Swedish unit costs were used. Haematopoietic response rates, defined as Hb level ≥12 g/dl or an increase from baseline of ≥2 g/dl without a history of transfusion 28 days prior to response, were used as the effectiveness measure.The probability of epoetin alfa exhibiting economic dominance (higher effectiveness and lower cost) and also being more cost-effective than darbepoetin alfa was estimated. Six separate sensitivity analyses were conducted where differet costs items, variances/correlations and etsimted response rates was tested. RESULTS: According to this model, epoetin alfa is associated with greater effectiveness than darbepoetin alfa. Mean haematopoietic response rate was 49.86% for epoeting alfa compared to 41.38% in darbepoetin alfa. Epoetin alfa is also associated with lower costs than darbepoetin alfa, Sek 31,661 compared to Sek 43,369 over 12 weeks of therapy. The probability that epoetin alfa exhibits economic dominance over darbepoetin alfa is estimated at 92.9% and the probability that epoetin alfa is more cost-effective is estimated at 99.9%. Sensitivity analyses suggest that the model is robust and, within the margins of uncertainty, not sensitive to modifications in the underlying estimates. CONCLUSIONS: This analysis suggests that epoetin alfa should be considered first for treating chemotherapy-related anaemia given its cost-effectiveness profile. Comparative efficacy of these agents should be further assessed in future head-to-head studies.