This work describes the polarographic behavior of hydrolyzed iron(III) solutions, mainly with respect to time and pH. The reduction of a high molecular weight compound (mol wt ∼ 6000–10 000) on mercury electrode is pointed out. The nature of this polymer is also studied by gel chromatography and light scattering. The usefullness of the voltametric techniques for the study of the hydrolyzed iron(III) is pointed out.