Sodium chloride solutions of concentration 15 and 30 g dm(-3) were electrolysed in a flow-through electrolyser with a titanium/TiO2/RuO2 anode at current densities 1059-4237 A m(-2). The current yield for the reduction of hypochlorite on a stainless steel cathode was found to be 13-32% at 7 g dm(-3) NaClO, in agreement with that calculated on the basis of the Stephan-Vogt theory. Migration of ions was taken into account, the diameter of hydrogen bubbles was set equal to 0.04mm and the coverage of the electrode with the bubbles was estimated as =theta 0.897. The results of calculations show that the reduction rate of hypochlorite at low NaCl concentrations is lowered by migration. Literature data for the reduction of hypochlorite are in accord with the current yield calculated on the basis of the Stephan-Vogt theory using theta = 0.787 and theta = 0.949.