Polymerization of acrylonitrile (AN) initiated by Ce(TV) was performed in an electrolytic cell. The precipitated polymer was formed in the cathodic compartment, and the reduced initiator was reoxidized in the anode, thus allowing for the continuation of the process. The effects of concentrations of the monomer, Ce(IV), and sulfuric acid (the electrolyte) were investigated as well as the potential and the temperature. The yield of the process, proceeding under mild conditions, was high. The study was augmented by voltametric and spectrophotometric investigation. The resulting polymer was characterized by FTIR and optical spectrometry, and its m.w. was determined by viscometric method. A possible mechanism of polymerization is suggested.