Coconut shell nanoparticles have been prepared via top-down approach from wet-stirred media mill. Milling parameters like milling time, feed concentration, effect of surfactants and surfactant concentration have been investigated for efficient production of nanoparticles. Particle size of nanoparticles was estimated from Particle Size Analyzer and chemical composition of raw and nanosized Coconut Shell Particles (CSPs) was analysed from Fourier Transform Infrared Spectroscopy. Particle size of nanoparticles was confirmed from Transmission Electron Microscopy (TEM), which also revealed the spherical morphology of the nanoparticles. X-Ray Diffraction patterns reflected presence of constituents of CSPs and crystallite size derived from it was comparable with the one obtained from TEM images. The work proposes an improvised and effective process of mechanical preparation over dry ball milling method to prepare nanoparticles.