Zn-Ni alloy coatings were electrodeposited on mild steel substrate from acidic sulphate bath. The effect of different electrodeposition parameters including temperature, current density, agitation speed and Ni2+/Zn2+ ion ratio on the Zn-Ni coating's physical, chemical and mechanical properties has been studied. Results show that Ni content of coatings has a strong effect on the structure, morphology and microhardness of coatings. Increasing Ni2+/Zn2+ ratio in the bath, higher temperature and higher deposition current density increased the Ni content of coatings. However, higher agitation speed increased the Zn electrodeposition and the anomaly of deposits. The phase structure of the coatings was strongly affected by the Ni content in the coatings. It changed from Zn rich eta phase to Ni5Zn21 gamma phase. Weak signal of delta-Ni3Zn22 phase was rarely observed for some coatings deposited at different parameters. Single gamma phase coatings with optimum properties were electrodeposited at 40 degrees C and 80 mA/cm(2), under 600 rpm agitation speed from the bath with Ni2+/Zn2+ ratio equals 1. Wear resistance of coatings were also improved by Ni doping. (C) 2014 Elsevier B.V. All rights reserved.