This chapter provides a review of mycorrhizal fungal diversity, which is beneficial for ecosystems owing to mutualistic symbiosis with the roots of various types of plants. This chapter also covers the different methods of isolation and identification of mycorrhizal fungi. These range from conventional methods to cutting–edge techniques, including biochemical, molecular, and functional genomics. The importance of different types of mycorrhizal fungi in ecological systems is well known; however, there are still ongoing efforts to effectively identify and isolate diverse species that play crucial roles in these symbiotic relationships. Current methods, although varied, often lack the precision and applicability needed to fully understand the complexity and diversity of mycorrhizal fungi. This chapter will also highlight the mycorrhizal diversity that will assist researchers in better understanding the symbiotic role of mycorrhizal fungi and their beneficial effects on the ecosystem. By the end of the chapter, readers will gain sufficient knowledge on both the diversity of mycorrhizal fungi and the various techniques needed to advance ecological research and use sustainable practices.