Nickel powders were prepared by the reduction of hydrazine of Ni(OH)2 reactant slurries from non-aqueous media. The morphological characteristics of nickel powders were investigated under various processing conditions. Nickel powders were characterized by using scanning electron microscope (SEM), X-ray diffractometer (XRD), thermal gravitational analysis (TGA) and X-ray photoelectron spectroscopy (XPS). The size of nickel powders was increased as the reaction temperature and time increased because of the thermal agglomeration of nuclei and/or increased growth rate. The surface of nickel powders composed of both Ni and Ni(OH)2 was oxidized in the temperature range of 400-600°C.