In this work, the effect of processing variables on the synthesis of WC nanoparticles by solvothermal route has been reported. Nanoparticles of tungsten carbide (WC) have been prepared by taking metallic magnesium (Mg), acetone (C3H6O), and tungsten trioxide (WO3) in an autoclave at 600 degrees C. The XRD results showed that the optimization of the reaction time facilitates the reduction as well as carburization of the tungsten source. The Williamson--Hall analysis was used to study the effect of synthesis time on the crystallite size and lattice strain of the sample. Differential thermal analysis/thermogravimetric analysis shows the stability of the synthesized product. It has been observed that the synthesis of WC nanoparticles is a multistep process and the complete carburization reaction occurs at particular carburization time.