Brain metastases are prevalent in solid tumours and lymphomas. They are associated with poor survival. The brain is regarded as a sanctuary site for metastatic tumour cells where they exist partially protected from drugs by the blood brain barrier. Amongst the different molecular sub-types of breast cancer, HER2 positive tumours and triple negative tumours exhibit the highest incidence of brain metastasis. Specific strategies are needed to fight brain metastatic disease. Preclinical models for brain metastasis have been developed, yielding mechanistic molecular knowledge and new therapeutic approaches.