**Abstract**

Immunotherapy has been demonstrably effective against various cancers, particularly those in the hematopoietic system and those with a high tumor-specific antigenic burden. Unfortunately, the development of immunotherapeutic strategies has proven more challenging against central nervous system (CNS) malignancies due to several unique characteristics of brain tumors that pose extraordinary barriers. To date, there is a lack of phase III trials demonstrating improved progressionfree survival (PFS) and/or overall survival (OS) using immunotherapies in brain cancers. However, a better mechanistic understanding of current resistance to immunotherapies along with data from novel innovative techniques to overcome these barriers has been encouraging. This chapter gives an overview of current immunotherapies in the development of brain cancers. We will evaluate the present studies available in the clinical setting and any of their potential findings. The chapter will also discuss pertinent preclinical strategies whose translation for human use would potentially prove efficacious or provide invaluable scientific discovery.

**Keywords:** immunotherapy, brain cancer, immune system, malignancy
