Brachytherapy delivers high doses of radiation to brain tumors while sparing normal surrounding tissue. It may be used as a primary treatment, an adjuvant treatment, or as therapy for recurrence of some malignant gliomas, low-grade astrocytomas, meningiomas, metastases, and pediatric brain tumors. Each of the three principal types of brachytherapy (high dose rate, low dose rate, and intracavitary) has advantages and disadvantages. Combining brachytherapy with another modality, such as hyperthermia, may improve results. Although radiosurgery is supplanting brachytherapy for many indications, brachytherapy remains a viable option. This article discusses the radiobiology, procedures, clinical applications, and outcomes of brachytherapy in managing brain tumors.