The dynamic properties of arrays of 1-D nickel nanowires (NWs) with high aspect ratio have been studied by ferromagnetic resonance technique using a flip-chip method in the frequency domain. The fundamental magnetic parameters such as spontaneous magnetization, gyromagnetic ratio $(\gamma)$ , Gilbert damping $(\alpha)$ , and magnetic anisotropies of the NWs of various lengths were determined from resonance frequency—field $[{f}_{{\rm res}}({H}_{0})]$ and frequency linewidth—field $[\Delta{f}_{{\rm res}}({H}_{0})]$ data. The effective fields of the NW system were observed to decrease slightly with the increasing length of NWs. The value of gyromagnetic ratio $(\gamma)$ increases from shorter length NWs and then saturates above 16 $\mu{\rm m}$ length NWs. From the $\Delta{f}_{\rm res}({H}_{0})$ data, we quantitatively determined Gilbert damping $(\alpha)$ . The value of $\alpha$ first increases for smaller lengths and then saturates for higher lengths ${>}{\rm 30}~\mu{\rm m}$ , which may be attributed to intrinsic and extrinsic relaxation contributions to linewidth. We observed the dc current $({I}_{\rm DC})$ effects on RF properties [ ${f}_{\rm res}(I_{\rm DC})$ and $\Delta{f}_{\rm res}(I_{\rm DC})$ data] of coplanar waveguide (CPW)-based NW structures. Resonance frequency as well as frequency linewidth decreased with increase in ${I}_{{\rm DC}}$ . We conclude that the Joule heating effect causes increase in temperature, which decreases saturation magnetization and anisotropy field $({H}_{\rm ani})$ , and hence there is a decrease of ${f}\!_{\rm res}$ and ${\Delta}{f}_{\rm res}$ with the increase of ${I}_{{\rm DC}}$ .