Breast cancer is the most common type of cancer among women in Denmark. In 15% of the patients with metastatic breast cancer (mBC) an overexpression of the HER2 protein on the tumour cells, amplification of the HER2-gene or both are present. HER2-positive mBC is associated with poor disease prognosis. The discovery of HER2 led to the development of HER2-targeting monoclonal antibodies significantly improving survival for patients with HER2-positive mBC as summarised in this review. The future brings even more HER2-targeting drugs, which further can contribute to the palliative treatment of HER2-postive mBC patients.