Background: Intravenous (i.v.) iron supplementation significantly improves the response to erythropoiesis-stimulating agent (ESA)-based therapies in patients with cancer- or chemotherapy-induced anemia. The economic implications of adding i.v. iron to ESA treatment are less well investigated. Published randomized controlled trials do not provide sufficient data for a comprehensive cost-effectiveness analysis. Methods: Preliminary cost calculations from the Swiss health care system perspective based on a meta-analysis and published results of eight randomized controlled trials without correction for decreased ESA need provide a conservative cost-effectiveness estimate. Results: The additional total cost of i.v. iron supplementation ranged from EUR 417 to EUR 901 per patient depending on the evaluated iron-carbohydrate complex. Considering a 24% absolute increase in the proportion of ESA responders, the incremental cost-effectiveness ratios per additional responder are EUR 1,704-3,686. In routine practice, better values may be achieved due to ESA dose savings. Conclusion: Supplementation of ESAs with i.v. iron appears to be an economically viable treatment option in anemic cancer patients. Additional research on ESA dose savings and cost-effectiveness is required.