The electrodeposition of copper indium diselenide has been studied in the presence of an excess of In(III) ions by voltammetric methods, X-ray diffraction analysis and chemical analysis of the deposits. It is shown that the presence of In(III) in the solution favours the reduction of Se(IV) to Se(II-) via the formation of CuInSe2. Two indium codeposition processes are observed. The first involves the formation of CuInSe2 + Cu2Se or CuInSe2 + In2Se3, depending on the ratio alpha of the Se(IV) flux to the Cu(II) flux. It corresponds to an easier reduction of CuSe into Cu2Se and Se(II-). The second codeposition process results in a mixture of Cu + CuInSe2. It corresponds to an easier reduction of Cu2Se into Cu and Se(II-). The phases obtained under various conditions of potential and flux ratio are given.