In this paper, the processes associated with the electrodeposition of bismuth antimony telluride thermoelectric films, were reported along with an analysis of the composition and crystallinity of the resulting films. The electrodeposition can be described by the general reaction 2(1− x) Bi 3++2 x Sb 3++3 Te +IV+18e −→(Bi 1− x Sb x ) 2Te 3. Cyclic voltammetry studies led to the determination of the deposition potential of the binaries systems Bi–Te, Sb–Te, and the ternary Bi–Sb–Te dissolved in 1 M perchloric acid and 0.1 M tartaric acid. The influence of the deposition potential and the electrolyte composition on film stoichiometry and their crystal parameters have been studied. It was shown that all stoichiometries of the solid solution Bi x Sb 2− x Te 3 can be easily adjusted by controlling the deposition potential and the electrolyte solution.