Preparation of copper and indium selenide thin films by electrochemical selenization of their respective vacuum-deposited metal layers is described. Growth of CuSe and InSe single-phase films was observed under varied selenization conditions of current density and SeSO32- ion concentration. Structural studies show that selenide film growth takes place by nucleation. The selenization process involved in the growth of CuSe and InSe films occurs by Se2- ion generation followed by ionization of the metal which in tum reacts to form selenide film. As a result excess Se incorporation in the film is prevented leading to the growth of stoichiometric films as confirmed by compositional studies. The kinetics of selenization is affected by the cathodic potential through the control of Se2- ion diffusion and modification of the space-charge layer in the vicinity of the metal.