Legumes are a key player in sustainable agriculture. They are a potential tool as forage for reclamation of saline soils. However, still there is a need to balance between tolerance of the forage during different developmental stages and its productivity. The present work aimed to study salinity tolerance of four wild Medicago species, as an initial step to select new species that can be grown in salt-affected soils or used as wild relatives to improve alfalfa. Seeds of M. polymorpha, M. intertexta, M. truncatula and M. lupulina, collected from different natural habitats, as well as alfalfa were germinated under different salinity levels to evaluate germination percentage and germination speed. Generally, seeds of M. truncatula collected from desert habitat showed the highest mean germination percentage followed by alfaalfa, while seeds of M. intertexta collected from salt-affected habitat exhibited the highest mean germination speed, followed by M. lupulina. Under severe salt stress, M. intertexta exhibited the highest aerial biomass index, followed by M. truncatula and M. lupulina, while M. polymorpha and alfalfa came as inferiors. Mineral contents and ion leakage of the studied species were determined and discussed. M. intertexta, M. truncatula and M. lupulina, collected from stressful habitats, tended to maintain osmotic and ionic homeostasis by relying on accumulation of the less energetic cost ions (Na+) in roots and sugars and K+ in shoots scoring the highest aerial biomass and tolerance index, orderly. Therefore, the results recommend cultivating these species in salt-affected lands or using them as wild relatives to improve alfalfa.