OBJECTIVES: In patients with one to four brain metastasis, if diameter < 4 cm, the standard treatment is whole brain irradiation (WBI) followed by stereotactic radiosurgery (SRS). There is growing interest on the delivery of isolated SRS, aiming to reduce side effects of WBI, despite a higher risk of intra-cerebral recurrences. The objective of this study was to compare the cost-effectiveness of those two strategies, under Brazilians third-part payers’ perspective. METHODS: A meta-analysis of summary data, including all phase III prospective trails that compared SRS to WBI+SRS, was performed. Data about recurrence management, dependant of on the lesion size, as well as of previous delivered treatment, were also extracted. Costs were estimated based on charges accordingly to Brazilian Health Care reimbursement rates for the private system (CBHPM). Only directs costs were considered, and were expressed in Brazilian Reais (BRL). A probabilistic sensitivity analysis was conducted to evaluate the robustness of the results. The perspective was that from the Brazilian Third Party payer.  RESULTS: Three phase III prospective trials have been selected, including 467 patients. Once there was no difference in overall survival, effectiveness was evaluated according to local control. After two years of follow up, 78% [64.2-87.4%] of the SRS patients and 53% [47-57%] of the WBI+SRS patients have recurred. The incremental cost-effectiveness ratio (ICER) comparing WBI+SRS to SRS was of 7.489,60 BRL/year without cerebral recurrences. Sensitivity analysis showed that ICER remains acceptable under a wide range of assumptions . CONCLUSIONS: Results suggested that WBI+SRS might be considered as a cost-effective strategy in patients with up to 4 brain metastases. Once no detrimental survival effect have been shown, SRS can be cost-savings for Brazilians third-party payers, but patients need to be aware of the risks involved in not delivering WBI.