Herein, copper nanoparticles were synthesized using electrochemical method at pH 5, 6.5, 9.5 and 12.5 (coded as Cu5, Cu6.5, Cu9.5 and Cu12.5, respectively). Copper was used as electrode whereas 0.15 M oxalic acid in aqueous solution was used as an electrolyte. Effect of pH of the electrolyte solution on the morphological, structural and textural properties of prepared copper nonoparticles was studied. Prepared nanoparticles were characterized by X-ray crystallography, Field emission scanning electron microscope, transmission electron microscopy, thermogravimetric analysis, differential thermal analysis and textural analysis. The morphology and sizes of the nanoparticles prepared varied with the initial pH of the solution. Sizes of synthesized Cu particles were found to be in the range of 20 nm to 7 μm. All the particles were mesoporous in nature. Cu5 was found to contain 67% copper hydroxide and 33% copper oxalate whereas Cu6.5, Cu9.5 and Cu12.5 essentially consisted of copper hydroxide. © (2015) Trans Tech Publications, Switzerland.