Copper (Cu) and iron (Fe) electrical contacts to gallium arsenide (GaAs) and indium arsenide (InAs) nanowires (NWs) have been fabricated via electrodeposition. For undoped or low carbon-doped (1017/cm−3), p-type GaAs NWs, Cu or Fe nucleate and grow only on the gold catalyst at the NW tip, avoiding the sidewalls. Metal growth is limited by the Au contact resistance due to thick sidewall depletion layers. For InAs NWs and heavier-doped, core–shell (undoped core-C-doped shell) GaAs NWs, metal nucleation and growth occurs on the sidewalls as well as on the gold catalyst limited now by the ion electrolyte diffusivity.