The electrodesulfurization of heavy oil feedstreams is accomplished wherein a heavy oil feedstreams, along with hydrogen, is passed the cathode side of an electrochemical cell wherein the organically bound sulfur compounds in the heavy oil are reduced and the sulfur is released as hydrogen sulfide. The hydrogen sulfide can be fed directly into the anode side of the electrochemical cell to produce sulfur and hydrogen or it can be passed to an oxidation zone containing an aqueous solution of an oxidized metal salt.