OBJECTIVES: To analyze the economic impact of the incorporation of pertuzumab for the treatment of metastatic breast cancer HER2+ in a University Hospital according to real data of our patients. METHODS: Cross-sectional study where the patients with breast cancer were analyzed in our hospital during one year (April 2013 to April 2014). The demographic data of the patients (age and weight) and antineoplastic treatments used were obtained from the computer program Hospiwin®. The dose and efficacy data have been obtained from the phase III CLEOPATRA trial. This clinical trial compares docetaxel + trastuzumab vs docetaxel + trastuzumab + pertuzumab with progression-free survival (PFS) 12.4 (CI 10.4-13.5) vs.18.5 (CI 16.6-21.6) months respectively.Costs of the drugs were included in the economic model developed in Excel® data base. The time horizon was one year and the perspective of medical leadership of the hospital was used. RESULTS: During the study period 371 patients were treated for breast cancer and 75 patients (20.2 %) were HER2+. The mean weight of 71.5 kg (SD = 17.1) and men BMI of 29.3 were obtained.The annual cost of docetaxel + trastuzumab + pertuzumab was  69,245.32 € vs 29,837.4 € (CI (in the docetaxel + trastuzumab treatment group. The cost per PFS per year was 44,964 € (CI 38,469-50,177 €) in the docetaxel + trastuzumab + pertuzumab group vs 29,837 (CI 26,640-35,948 €) in the docetaxel + trastuzumab treatment group. The incremental cost effectiveness ratio (ICER) was 15.127 € /PFS per year.  CONCLUSIONS: The addition of pertuzumab to treatment with docetaxel / trastuzumab for metastatic breast cancer has shown an increase in SLP. However, the economic impact of this new drug, requires careful selection of patients who could benefit. Health authorities will have to consider whether pertuzumab is cost-effective in terms of their willgness to pay.