Optimum treatment for patients with primary CNS lymphoma remains challenging because there have not been any large randomised clinical trials of this rare tumour. Drugs used in treating systemic non-Hodgkin lymphoma have mostly proven ineffective because of difficulties crossing the blood-brain barrier. The recognition of the efficacy of high-dose methotrexate was a substantial therapeutic breakthrough and further advances, such as the development of polychemotherapy regimens, have built on this. Whole-brain radiotherapy can consolidate response to chemotherapy, but the associated toxic effects of chemoradiation can be unacceptable. Other effective approaches include disruption of the blood-brain barrier and the use of high-dose chemotherapy. Recently, there have been attempts to optimise multi-drug chemotherapy regimens by focusing on improving survival and reducing toxic effects. A promising area of research is the incorporation of novel targeted drugs into standard treatment frameworks. In the future, greater cooperation between research groups should hopefully lead to further therapeutic advances.