In minimally invasive surgery, especially in neurosurgery, the ability to reach deep and functional structures without damage remains a major challenge. Recent breakthroughs in microtechnologies have enabled the downsizing of an increasing number of devices. In such a context, the possibility to navigate a micromedical device inside the human brain is a reachable ambition. One of the most expected applications is the identification and the treatment of early-stage cancers which could strongly improve therapies efficiency. Despite these remarkable attainments, micromachines, to actually become revolutionary, require a tracking system at least as accurate as its size and working in an heterogeneous environment. The aim of the present paper was to provide an overview of the state of the art in medical device tracking systems for the brain. Firstly, the latest advances are categorized by technological family: magnetic field, electromagnetic waves, magnetic resonance, ultrasound waves and hybrid solutions. Secondly, in a comparative purpose, performance criteria are evaluated and displayed in radar diagrams and graphs to highlight the three dimensions challenge the systems should take up: performance, invasiveness and user experience. Finally, the present and future of each localization family are provided.