The electrochemical oxidation of aqueous solutions of hydrogen selenide (HSe-) and of hydrogen polyselenide ions (HSex-) on glassy carbon electrodes at pH = 9.2 is reported. In both cases, the oxidation leads to deposits of selenium. The role of polyselenides as intermediates in the process is demonstrated. At 25 degrees C amorphous selenium is formed whereas at 70 degrees C crystalline selenium is deposited. The possible use of selenium films for technological purposes is discussed.