The prognosis for patients diagnosed with malignant brain tumors has remained dismal despite advances in both neuroimaging and conventional treatment modalities. The use of biodegradable polymers for controlled local delivery of antineoplastic agents represents a major advance in the treatment of brain tumors. By implanting polymers loaded with chemotherapy agents directly onto the brain tumor resection bed, therapeutic doses of a drug can be administered intracranially for prolonged periods of time meaning high systemic doses associated with debilitating toxicities can be avoided. This technological advance has expanded the spectrum of available treatments for neoplasms of the CNS and has facilitated new approaches for the treatment of malignant brain tumors.