We have studied the effect of the substrate on the structural and electrical properties of Ni thin films. Series of Ni thin films have been prepared by dc diode sputtering on four different substrates, glass, Si(111), Si(100) and mica; the Ni thickness ranges from about 47 nm to 317 nm. We observed that Ni grown on glass has no texture. On the other hand Ni deposited on Si gets the 〈111〉 preferred orientation for all samples, even the thinner ones. Grain sizes were found to increase with increasing thickness for Ni/glass and Ni/Si(100), with the grains in Ni/Si(100) much larger than the corresponding ones for Ni on glass. The lattice constant of Ni on glass is smaller than that of the bulk. For the Ni on Si, however, the lattice constant is practically equal to the bulk value. We noted that the resistivity ρ decreases with increasing thickness and with increasing grain size for practically all samples. Also the Ni thin films deposited on a semiconductor substrate (Si(100) and Si(111)) get a higher resistivity than Ni on an insulator (Ni/glass for example) for the same Ni thickness. No magnetoresistance was observed in these Ni thin films at ambient temperature and for about a half kOe perpendicular magnetic field. These experimental results will be interpreted and discussed.