Although Pistachio (Pistacia vera) is classified as a salt tolerant plant, in recent years pistachio production has reduced, due to the drought and the low quality of irrigation water. The role of hydrogen sulfide in the defense mechanisms of plants under abiotic stresses indicates that this compound can reduce the salinity stress in plants. So, a greenhouse experiment was conducted to evaluate whether application of hydrogen sulfide would protect pistachio seedlings subjected to salt stress. The treatments were four levels of salinity (0, 40, 80 and 120 mM) and four concentration of hydrogen sulfide (0, 0.4, 0.8 or 1.2 mM). The results showed that salinity stress reduced shoot and root dry weights in pistachio seedling. Increasing NaCl concentration caused increasing proline and carbohydrate content and reduced the leaf relative water content and chlorophyll content in pistachio rootstocks. The use of hydrogen sulfide increased proline and relative water content and chlorophyll content of leaves compared with the control. The application of hydrogen sulfide at 1.2 mM resulted in increased carbohydrate concentration in pistachio seedling under salinity stress. Although increasing NaCl concentration caused increasing catalase and ascorbate peroxidase activities in salt tolerant pistachio seedling, application of hydrogen sulfide significantly increased the antioxidant enzyme activities. Overall, it could be concluded that applied hydrogen sulfide ameliorated the adverse effects of salt stress through preventing decrease in leaf chlorophyll and relative leaf water content, and increasing in carbohydrate, and antioxidant enzyme activity in pistachio seedlings.