Rapid solvent-free mechanochemical synthesis of CTS nanocrystals from elemental precursors is reported herein. The process is completed in 15 min, proceeding through immediate formation of CuS in a self-sustaining manner and its subsequent reaction with Sn and residual sulfur. The reaction progress was monitored by pressure and temperature changes in the milling vessel, X-ray diffraction, Soxhlet analysis, grain size analysis and electric resistivity measurements. The relationship between the consumption of metallic precursors, grain size and electrical resistivity is provided. The final product was nanocrystalline with crystallite size below 10 nm, as confirmed by both X-ray diffraction and transmission electron microscopy. The nanocrystals are agglomerated into micrometer-sized grains. It exhibits poor porous properties with the specific surface area value of 2.5 m(2)/g. The X-ray photoelectron spectroscopy has shown that the surface is significantly oxidized, due to milling in air. The optical properties of the prepared CTS nanocrystals are interesting for photovoltaic applications.