A short non-exhaustive overview of hexacarbonyl dithiolate di-iron species and of their substituted derivatives relevant to the chemistry of the di-iron sub-site of the hydrogenase enzymes is presented. Although few detailed electrochemical studies have been reported until now, we discuss the use of di-iron organometallic species as catalysts for the electrochemical reduction of protons. Finally, we propose targets for the synthesis of more efficient biomimetic catalysts. © 2004 Elsevier B.V. All rights reserved.