Here we report a one-pot route for the synthesis of nickel dodecahedra with 52.3 ± 0.1 emu g(-1) of saturation magnetization. The procedure is very simple, and only three chemicals (NiCl2·6H2O, isopropanol and polyvinylpyrrolidone) are used throughout the entire synthetic process. During the reaction, it is believed that the application of isopropanol and the amount of polyvinylpyrrolidone play an essential role in forming the dodecahedral morphology of the final product. Furthermore, a formation process of twinning and the influence of reaction kinetic factors were proposed to explain the formation of nickel dodecahedra.