OBJECTIVES: The objective of this study was to estimate Incremental Cost-Effectiveness Ratio (ICER) of utilizing eribulin mesylate (Halaven®) for metastatic breast cancer (MBC) in the Mexican public health institutions for third line (3L) treatment of patients who have been previously treated with capecitabine. METHODS: Eribulin mesylate is indicated in Mexico for the treatment of patients with locally advanced or MBC that have progressed following treatment with an anthracycline and a taxane and have had at least two chemotherapeutic regimens in an advanced setting. An economic model was developed to evaluate the cost-effectiveness of eribulin mesylate in the population previously treated with capecitabine. Data on progression free survival and overall survival were derived from a randomized clinical trial of eribulin mesylate against treatment of physician choice (EMBRACE).  Analyses were prepared based on the sub-group of patients previously treated with capecitabine. A five year partitioned survival model was developed to estimate the ICER of patients in this sub-group. Frequencies of adverse events and utilization of direct medical resources were also obtained from EMBRACE. Local Mexico tariffs were applied for all costs i.e. drug, administration and monitoring costs, adverse event treatment and palliative care. RESULTS: Incremental life years (LYs) gained by these patients was 0.28 life years, which is 3.36 months. At a cost of eribulin mesylate of 4,754 Mexican pesos per 2ml vial, the ICER per LY was 22,017 Mexican pesos. Sensitivity analysis results were also consistent with the base case findings. CONCLUSIONS: With a threshold of 140,000 Mexican pesos per life year saved, eribulin mesylate was found to be cost-effective for the population in line with license and that have been previously treated with capecitabine. Given the limited number of effective therapeutic options available to these patients, cost effective eribulin mesylate (Halaven®) represents a valid option for optimizing the treatment pathway.