HER2- positive breast cancer is a particularly aggressive form associated with faster disease progression and shorter survival rate if the disease is not treated. This type of cancer is characterized by excessive production of the HER2 protein, which promotes faster growth and division of cancer cells. The decision on treatment is made based on the characteristics of the tumor, the stage of the disease and the characteristics of the patient, as well as on their wishes and needs. This thesis contains an overview of approved therapeutic options for the treatment of HER2- positive tumors, as well as new therapeutical options that are currently in research phases. For most patients, chemotherapy in combination with trastuzumab and pertuzumab is the first- line treatment followed by trastuzumab emtansine as the second-line treatment. However, in selected patients, anti-HER2 therapy without chemotherapy can also be considered as an option. Several new anti-HER2 therapies remain available as the third-line, including tucatinib, neratinib, trastuzumab-deruxetan and margetuximab. In addition, new drugs and combinations currently under investigation show promising results, although the bar for improving overall survival (OS) with new agents is very high and challenging.