Introduction Brain tumors remain especially challenging to treat due to the presence of the blood–brain barrier. The unique biophysical properties of nanomaterials enable access to the tumor environment with minimally invasive injection methods such as intranasal and systemic delivery. Methods In this review, we will discuss approaches taken in NP delivery to brain tumors in preclinical neuro-oncology studies and ongoing clinical studies. Results Despite recent development of many promising nanoparticle systems to modulate immunologic function in the preclinical realm, clinical work with nanoparticles in malignant brain tumors has largely focused on imaging, chemotherapy, thermotherapy and radiation. Conclusion Review of early preclinical studies and clinical trials provides foundational safety, feasibility and toxicology data that can usher a new wave of nanotherapeutics in application of immunotherapy and translational oncology for patients with brain tumors.