OBJECTIVES: Breast cancer is known to be one of the leading causes of death among the female population.Preventive measures may provide an economic and outcome advantage by reducing treatment costs and increasing survival. The objective of this study was to evaluate the cost effectiveness of a breast cancer vaccine versus current standard treatments. METHODS: TreeAge software was used to calculate the cost-effectiveness. A decision tree was constructed for different probabilities of success and failure for the vaccine versus standard treatment.  Costs and outcomes (life years saved) ranges were obtained from published clinical trials. The vaccine effectiveness was projected from animal studies, with human clinical trials expected within a year. The range of effectiveness of the vaccine was considered between 30% and 90% with a baseline at 80%. The costs included for standard treatments ranged from $20,000 to $45,000 and the cost of the vaccine was assumed at $450 for three doses therefore, the cost for vaccine ranged from $300 to $2000 depending in the number of doses. The incremental cost effectiveness ratios were calculated from the range of costs and outcomes .Sensitivity analyses were performed to determine the robustness of the findings. RESULTS: Vaccination was found to be a potentially cost-effectiveness option with an ICER of 2384.146 relative to standard treatment. The incremental effectiveness was 8.2 life years saved.  The highest cost-effectiveness of the vaccine was at 90% success and a cost of not more than$1000 per individual. Sensitivity analyses indicated that the vaccine remained cost-effective over the range of model parameters. CONCLUSIONS: The breast cancer vaccine was projected to be the most cost-effective treatment option in this analysis. It is expected that better screening for breast cancer vaccine patient candidates will be available in the future.