Medicago arborea (Fabaceae) is a perennial shrub which grows throughout the Mediterranean basin, well adapted to semi-arid condition, and is used widely to provide forage. Its germination responses to environmental stresses are poorly understood. To determine the effects of salinity and temperature, we conducted germination tests of M. arborea seeds in controlled conditions. We varied the salinity (0, 50, 100, and 150 mM NaCl), within three ranges of alternating temperatures (10–20, 15–25, and 20–30 °C). Results indicate that seeds can germinate at high salt concentrations (150 mM NaCl). However, highest germination percentages were obtained in distilled water. The optimal temperature of germination corresponds to 15–25 °C, while low and high temperatures significantly inhibited the germination of seeds at all NaCl concentrations tested. Rate of germination decreased with increases in salinity. At higher thermoperiod the rate of germination was significantly lower in comparison to lower thermoperiod. These results suggest that M. arborea has potential utility as a forage shrub in saline environments.