The electroless cobalt coatings on mild steel have been studied by weight gain method, corrosion studies by potentiodynamic polarization measurements and hardness by Vickers microhardness tester. The influence of surface roughness has greatly contributed for corrosion and tensile strength of the coatings. SEM and XRD measurements were performed to study the surface morphology of cobalt coatings on mild steel. © 2014 University of Manchester and the authors.