Pulsing electrolysis is a method to produce high purity nano copper powder. Effect of 5 organic additives, polyvinylpyrrolidone (PVP), sodium dodecyl sulfate (SDS), polyethylene glycol (PEG), cellulose and thiourea (Tu) in 4 concentrations was studied. It was found that the PVP and SOS remarkably influenced the reduction of mean particle size while PEG and cellulose had slight effect on the mean particle size. Thiourea negatively affected the copper powder and resulted copper sulfide instead of pure copper powder. Produced powder was characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDS) and laser particle size analyzer (LPSA). Among the additives which were studied, the best one was PVP at 2 g/L and the mean particle size was 110 +/- 10 nm. (c) 2013 Elsevier B.V. All rights reserved.