Recent 15 years were dedicated to the investigations of Co-bearing massive sulfides associated with ultramafic rocks of the Middle Atlantic Ridge. These discoveries allowed to look in a new way at the genesis of ancient Co-bearing massive sulfide deposits from the South Urals and also from the different fold belts of the World. It’s shown that Co-bearing massive sulfides could be a separate type of massive sulfide deposits and they also could include several subtypes according to host rocks, ore textures/structures, ore mineralogy and geochemistry.