A commercial process for synthesis of spherical cobalt nanopowder has been developed. Based on laboratory scale experimental data, pilot plant production and reproducibility of the developed process has been investigated and optimized. Cobalt nanopowder were synthesized from reduction of cobalt sulfate salt, using hypo-phosphorous acid as a reductant in solution of sodium hydroxide. The effect of various process parameters on morphology and structure of the cobalt nanopowder synthesis, both at laboratory scale and pilot scale processes were optimized and compared. The developed proposed flow sheet is a techno economical feasible process for commercial production of spherical cobalt nanopowder in the range of 100-300 nm size. An indigenous designed pilot plant, capable of handling 30 L solution per batch has been developed. (C) 2014 Elsevier B.V. All rights reserved.