In this work, we reported a comparative study of nickel electrodeposition mechanism on indium tin oxide (ITO) from two mediums. The nitrate electrolyte contains 0.01 M of nickel nitrate hexahydrate (Ni (NO₃)₂, 6H₂O) with 0.1M of potassium nitrate (KNO₃)and chloride bath was a mixture of 0.01 M (NiCl₂, 6H₂O) with 0.1 M of potassium chloride (KCl). The electrochemical techniques cyclic voltammetry (CV) and the chronoamperometry (CA) revealed that the electrodeposition of nickel (Ni) at a negative potential around -1.1 V versus SCE (saturated calomel electrode) is quasi-reversible reaction controlled by the diffusion process in the two mediums. The experimental current transient curves are compared to those calculated from Scharifker-Hills models; it was found that the nucleation and growth of Ni on the ITO substrate follows an instantaneous three-dimensional (3D) mechanism in the two solutions, which was confirmed by the micrographs of SEM analysis. The X-ray diffraction characterization of nickel thins films elaborated by chronoamperometry on ITO substrate had shown a cubic crystal structure whatever the electrolyte composition. However, in nitrate solution the formation of a nickel oxide was identified.