Eriophyoid mites are economically rendered as the second most important mite species after tetranychid mites (Van Leeuwen et al. 2010). These ancient tiny creatures are very diverse due to their high host specialization (de Lillo et al. 2018) with more than 5000 species in the world which have been classified into three families Phytoptidae, Eriophyidae and Diptilomiopidae (Chetverikov et al. 2015; Bolton et al. 2017; Xue et al. 2017; Zhang 2017). Many of them are major pests and some are vectors of plant pathogens. Therefore, because of their high importance, the eriophyoid mite fauna was surveyed in Sari county, Mazandaran province, North of Iran, from 2017 to 2021. Samplings were done on most abundant plant species by first author and the sampling details have been listed in Table 1. The mites were recovered from the plant material by means of a modified washing method developed by Monfreda et al. (2007). We applied the methodology described in Mehri-Heyran et al. (2020) for slide mounting. The genera classification follows Amrine et al. (2003) and comparisons were also made with new genera of Eriophyoidea described since that publication. Host plant names and their synonymies are in accordance with "The World Flora Online" (2022).In total two families, five subfamilies, eight tribes, 24 genera and 42 species were collected and identified, and here the information about the collected specimens is provided. The examined materials are deposited at the Acarology Laboratory, Department of Plant Protection, Faculty of Agriculture, University of Tabriz (Iran), and at the Acarology Laboratory, Department of Plant Protection, Faculty of Agriculture, Azarbaijan Shahid Madani University, Tabriz (Iran).