The electrogeneration of hydrogen peroxide via reduction of dissolved oxygen was carried out in a three; dimensional electrochemical cell using graphite grains as cathode material and combined with the enantioselective oxidation of thioanisole to (R)-methylphenylsulfoxide catalyzed by Chloroperoxidase from Caldariomyces fumago. The relevant parameters for process development (e.g., conductivity of the biotransformation medium) were identified and optimized, leading to an efficient electroenzymatic process with a space-rime yield of 104 g.L-1.d(-1). The isolated product was produced on gram scale (1.2 g, purity >98%, ee > 98.5%).