Nanomedicine is a field where the progression of nanotechnology is recruited to serve health and medicine. It has opened new avenues to understand and tackle many sorts of interactions between the living tissues, which were undoable with macroscopic materials. Nanomedicine took neuroscience to a next era, where targeting many neurological and psychological diseases became no longer a challenging task. Many recent types of nanoparticles became able to cross the blood brain barrier and targeting specific brain areas. Brain disorders including Alzheimer, Parkinson, schizophrenia and others were found to be strongly connected to neuroinflammation, and accordingly to immune cells of the central nervous system, microglia that play a key role in neuroinflammation. However, their mechanisms of action are not fully understood, and hence, recent studies are competing to solve this mystery using nanoparticles as a helping hand. In this review, we summarized the use of nano drug delivery systems to target microglia in different neurodevelopmental and psychological disorders aiming that research could take a step further towards achieving improved brain targeted drug delivery.