Cathodic electrodeposition of PbSe from acidic aqueous electrolytes containing Se(IV), Pb(II) and Cd(II) has been investigated. It has been found that [100] oriented growth of PbSe: crystallites takes place in some regions of Pb(II) and Cd(II) concentration. Electrosynthesis has been carried out under conditions of underpotential deposition of lead adatoms (Pb-ad) and overpotential deposition of Se. It has been established by cyclic voltammetry that at electrodeposition potential E = -0.30 V (versus Ag/AgCl) underpotential deposition of Cd-ad on Se atoms of the PbSe structure also takes place. Adsorption of Cd-ad and Pb-ad is irreversible due to the formation of the chemical bonds Cd-ad-Se and Pb-ad-Se. The presumption has been made that the mechanism of the Cd(II) effect consists in selective adsorption of Cd-ad on faces of PbSe crystals and inhibition of underpotential deposition of Pb-ad.