Mechanical activation before carbothermic reduction can substantially enhance the formation of SiC from SiO2 and carbon mixtures. However, the morphology (e.g., particles or whiskers) of SiC formed from mechanically activated SiO2 and carbon mixtures is dependent of the degree of mechanical activation and the condition of the subsequent carbothermic reduction. These phenomena are investigated and rationalized based on the increased reactivity of the reactants and SiC formation mechanisms.