Hydrogen peroxide is produced by oxidizing alkylammonium salts of sulfonic acid-substituted anthrahydroquinones. As said salts are highly soluble in protic polar solvents such as water and lower aliphatic alcohols, the concentration of hydrogen peroxide in the reaction product thereby obtained may be advantageously high. The anthraquinone salt co-product generated by such oxidation may be readily converted in high yield back to the starting anthrahydroquinone salt by hydrogenation.