The electrodeposition of niobium from NbCl5 or K2NbF7, dissolved in molten alkaline fluorides (LiF/NaF), in the 700-800 degrees C temperature range has been studied by using cyclic voltammetry, chronopotentiometry, and chronoamperometry. A linear relationship between the Nb-IV diffusion coefficient and the temperature was found in the cyclic voltammograms and chronopotentiograms. Scanning electron micrography shows that the shape of the nuclei is hemispherical. Chronoamperometric results show that the deposition process involves instantaneous nucleation with diffusion-controlled growth of the nuclei. The influence of temperature, overpotential, and substrate (copper, stainless steel, vitreaus carbon) on the nuclear site densities is also considered.