The etiology of brain tumors is not completely understood, but several studies are in progress trying to establish possible risk factors as well as links to environmental changes and lifestyle. Brain tumors can be primary malignancies, meaning they start in the brain, or can be secondary malignancies, also called metastatic, meaning they are tumors with origin in other organs that have spread to the brain. The majority of brain tumors are secondary or metastatic. Knowing the origin of the primary cancer is critical, because it gives clinicians information about tumor behavior and delineates the best treatment course. Treatment modalities for neurologic cancer include surgery, radiation, chemotherapy, and immunotherapy, with the best results obtained when a multimodal approach is delivered. Advances in imaging technology offer fast and accurate diagnoses, intraoperative guidance, and optimal treatment evaluation. Consequently, healthcare providers are faced with the responsibility and challenges of staying up to date on emerging techniques and treatments in order to deliver the best patient care possible. This chapter provides nurses, residents, physicians, and all oncologic medical providers with important background on brain tumors and neurosurgery, specifically craniotomies and the unique anesthetic techniques that are commonly utilized during the most common neurosurgical procedures.