Silver nanowires (Ag NWs) are of great importance for modern applications as a substitute for indium tin oxide (ITO) when flexible, transparent conductive electrodes are required. In this paper, we report for the first time the electrical resistivity (ρ) of an isolated Ag nanowire not supported on a substrate, measured using transmission electron microscopy (TEM). Our results show a resistivity value on the order of 10⁻⁷ Ω-m, which is significantly higher than that of the bulk silver, which is 1.59 × 10⁻⁸ Ω-m. We attribute the reduction in electrical conductivity to three main factors: (i) surface scattering, (ii) internal boundaries, and (iii) internal stress. The electrical conductivity of Ag/Ni nanowires was also evaluated. The deposition of Ni layers onto Ag NWs forms a core–shell structure, resulting in a slight decrease in resistance comparable to Ag nanowires. This indicates that electrical transport is mainly governed by the highly conductive Ag core, whereas the Ni shell plays an indirect role through structural stabilization and modulation of surface states and scattering mechanisms, rather than directly enhancing intrinsic conductivity.