Optical techniques are becoming increasingly important in healthcare, as both therapeutic anddiagnostic tools. In neurosurgery, photonic technologies such as the microscope have alreadyfound widespread use. The overall aim of this paper is to give an overview of optical monitoringmethods and their implementation and use in stereotactic and functional neurosurgery. Thedevelopment steps presented in this paper range from radiofrequency-lesion size estimationusing optics to a system adapted for neurosurgical intraoperative navigation during stereotacticdeep brain stimulation (DBS) lead implantations. The two main optical methods implemented asintraoperative guidance tools are laser Doppler flowmetry and diffuse reflectance spectroscopy.By combining these fundamental methods with probe designs adapted to stereotactic systems,vessels can be tracked and “bar-codes” of tissue type along pre-defined trajectories used for DBSimplantations identified. Examples of the optical methods used in relation to stereotactic DBSimplantations are given.