Manuscrito recibido el 21 de noviembre de 2014. Aceptado, tras revisión, el 4 de junio de 2015. AbstractIron oxide nanoparticles and in particular Fe3O4 Nanoparticles are new materials used in biotechnology and nanotechnology, Food and drugs administration has approved several coated and bare Iron oxide nanoparticless and they are actually used in biomedical applications as: Magnetic Resonance Imaging contrast agent, Thermotherapy agent, Drug carrier for cancer treatments, and so on.All this applications bring risk of: a single exposure, workplace exposure, incidental and environmental release and potential long life use. In this regard, iron oxide nanoparticles toxic effect, in particular neurotoxicity is not well known and it needs to be assessed.The aim of this review is to present several iron oxide nanoparticles in vitro and in vivo studies that reflex Fe3O4 actual an overview toxicological profile.