Precipitation is a hopeful process for nanoparticle production due to rapid expedient, highly economic and uncomplicated. Barium sulphate nanoparticles were prepared through precipitation process via barium chloride and sodium sulphate as the reagents in water-benzene reaction medium. Eight different compositions of mixed solvents, including pure water, 20 vol. %, 30 vol. %, 50 vol. %, 70 vol. %, 80 vol. %, 90 vol. % and 95 vol. % of benzene were practiced. The effects of the volume percentage of benzene in the aqueous medium on the resultant barium sulphate nanoparticles were scrutinized. The products were characterized through X-ray diffraction (XRD), Field Emission Scanning Electron Microscopy (FESEM) with Energy Dispersive X-ray Spectrum (EDX) and Fourier Transform Infrared Spectroscopy (FTIR) techniques. The synthesized nanoparticles are well dispersed and they exhibit an orthorhombic structure and spherical in morphology with an average size of 35.9 nm. From this we establish, water-benzene mixed solvent inhibits barium sulphate nucleation growth.