This paper presents the current state of our knowledge of mutual legume intercrop- ping, with an emphasis on its utilization in continental and Mediterranean climates. Its novelty is primarily re fl ected in the carefully designed schemes for two main forms of mutual legume intercropping. The fi rst one is establishing perennial forage legumes, such as red clover, alfalfa, and sainfoin, with annual legume, such as pea, where the latter acts as a bioherbicide and concurrently contributes to the total forage yield in the fi rst cut of the former. Another form is intercropping annual legumes with each other respecting the same time of sowing, that is, in fall or in spring, similar growth habit, especially stem length, time of maturity for cutting or harvest, and that one component has good standing ability and supports the other one that is susceptible to lodging. Since the prominently pioneering character of this research, most of the presented results, both published and unpublished, shown here for the fi rst time, deal with forage and grain yield and its economic reliability in the form of land equiv- alent ratio, since this would surely be of the primary interest to the farmers to get intro- duced with. The fi rst and rather advanced efforts have also been made in the physiology, anatomy, and biotic stress of both forms of mutual intercropping schemes. We anticipate that, together with further research in the said fi elds along with under- ground aspects, will make mutual legume intercropping one of the most promising answers for protein-rich food and feed worldwide.