Anthropogenic and natural activities-based ecosystem disturbances lead to leftover degraded barren lands. Ectomycorrhizal (ECM) fungi play an important role in regulating the nutrient balance of the terrestrial ecosystem, assisting plant regeneration on disturbed lands by conferring improved tolerance against various biotic and abiotic stresses. There are several challenges and knowledge gaps in utilizing the ECM fungi for large-scale ecosystem restoration programs. For strengthening the successful utilization of ECM fungal applications in out-fields, this chapter has summarized the various applications, mechanisms, and considerable important parameters of ECM symbiosis in regenerating and improving host plant growth against diverse stress conditions such as drought stress, heavy metal stress, and forest fire, thus leading to the rehabilitation of degraded lands. Above all, the major challenge remains the production of large-scale ECM fungal inocula for restoration programs. This chapter has summarized the various ECM inoculation techniques, including their merits and demerits. This chapter also highlights the essential role of ECM fungi in nutrient dynamics of host plants with soil and ECM fungal application as biofertilizers in agriculture and commercial nurseries, thereby replacing harmful chemical fertilizers.