Stereotactic neurosurgery is a means of operating by remote control, ie using a probe to an unseen target and then to therapeutically manipulate that probe by computer calculations and graphics. Functional neurosurgery is a technique designed to: a) restore normal conductivity in malfunctional nerve fibres or to improve blood flow in nerve tissue; or b) to alleviate mental illness. Due to the development of new technologies, such as CT and MRI-scans and computerized work stations, the general use of these procedures has increased, and all residents are now exposed and trained in stereotactic and functional technique. This work covers the dynamic area of neurosurgery. It is divided into several sections dealing with technique, classical functions, stereotactic surgery, non-stereotactic functional neurosurgery, and the use of sterotactic technical overview. This is followed by the clinical application of procedures in the treatment of movement disorders, intractable pain, psychiatric illness, deep tumours, vascular malformations, epilepsy and tumours.