The problem of nonuniformity of pore filling in the template synthesis of nanowires is considered. The effect of the applied gradient of temperature on the instability of pore filling is analyzed. The model proposed takes into account the presence of outer thermal boundary layer and outer diffusion layer. The metal electrodeposition in porous template under the quasi-steady-state conditions is considered. The role of the temperature dependences of the exchange current density and the diffusion coefficient of metal cation is revealed. The deposition modes at which the initial dispersion of nanowire lengths can be reduced are determined. (C) 2018 Elsevier Ltd. All rights reserved.