Craniotomy is the fundamental technique used in tumor resection. It involves making an incision in the patient's scalp and then an opening in the skull. This is done using highly specialized drills. This opening allows access to the intracranial cavity where the brain is located. Once this access has been achieved, the tumor may be resected.

Tumor resection is often guided using computer aided stereotactic techniques. These techniques make use of a computer system that incorporates information from diagnostic tests such as MRI and CT scans to aid in intracranial navigation. Use of stereotaxis allows precise placement of the scalp incision and bone opening to allow optimal access to a tumor. This precision permits minimally invasive surgical techniques. As surgical openings have become smaller, associated morbidity has declined.

Another advantage to stereotaxis is the ability to navigate within brain and tumor tissue. The use of stereotactic equipment and methods allows the safe removal of deep-seated tumors in regions such as the thalamus and basal, which were often considered inoperable in the past. Despite such advances, some tumors should not be resected, either because of their location or their degree of infiltration of functional brain tissue. In such cases, a stereotactic biopsy may be indicated to make or confirm a suspected diagnosis and guide more definitive treatment. Specific descriptions of these techniques are provided below.