Nanoscale silicon (Si) is a promising material for many advanced technologies such as batteries, thermoelectrics, and solar cells. However, the current methods for fabricating this material are expensive, complex, and are difficult to scale up. The present work focuses on using mechanically activated self-propagating high-temperature synthesis (MASHS) of nanosilicon using silica (SiO2) and magnesium silicide (Mg2Si) as the precursors. During mechanical activation, SiO2 and Mg2Si are ball-milled together for a short time. Then the mixture is compacted and ignited, which results in a self-sustained propagation of the combustion wave over the sample leading to the formation of nanosilicon and magnesia. The magnesia is leached in diluted hydrochloric acid. Also, the addition of sodium chloride (NaCl) to the mixture, decreases combustion temperature and particle size of the formed Si.