A fundamental effort in neurosurgery is to reduce surgical trauma. Microneurosurgical technique combined with precise localization of lesions, can minimize the invasiveness of neurosurgical procedures. This report summarizes the utility of frameless neuronavigator systems and examines their value in reducing operative invasiveness. The basic principle of neuronavigation is the virtual linkage between digitized neuroradiological data and real anatomical structures, allowing an excellent three-dimensional orientation by real-time graphic-anatomic interaction. As frameless graphic interactive neuronavigation is developed further, these devices should become an important component of the modern microneurosurgical armamentarium and reduce surgical morbidity.