Soil biodiversity is fundamental for the correct functioning of the ecosystems, since it is the basis for vegetation development and habitat creation. In this context, soil mesofauna has been proposed as a bioindicator for soil health because of its sensitivity to soil-condition alterations. However, there is still a lack of information on the edaphic communities of several ecosystems all around the world. Therefore, the objective of this study was to assess the edaphic mesofauna in different oak forests of the Atlantic area of the Iberian Peninsula: Quercus faginea (Basque Country, Spain), Q. robur (Galicia, Spain), and Q. rotundifolia and Q. pyrenaica (Bragança, Portugal). All these forests were demonstrative areas of the LIFE SILFORE project. All the forests were sampled in 2025 spring: soil samples were collected and then sent to NEIKER, where the mesofauna was extracted and characterized (to order level and mites to superfamily/family level). Overall mesofauna abundance, diversity (Shannon), richness, and Soil Biological Quality Index (QBS) were calculated, as well as Oribatida mite, Mesostigmatida mite, Prostigmata mite, and springtail (Collembola) abundance. Results showed that the overall mesofauna community (to order level) was similar between the analysed forests, with the mites and springtails being the dominant groups in all of them (between 89-93% of the whole community). Mesofauna abundance was highest in Q. pyrenaica forest (W= 8.74, p=0.013), due to a higher abundance of springtails (W= 9.52, p=0.008), but mesofauna diversity, richness, and QBS index did not show significant differences. When analyzing only the mite community, results were different: the community composition differed between all the oak forests (F= 3.93, p <0.001). In conclusion, all the analyzed oak forests had a similar soil health and a similar mesofauna community composition at a high taxonomic level. Moreover, when assessing the mite superfamilies/families, all the forests had a different composition, which shows the natural variability that these ecosystems might show due to various factors, such as soil typology and tree species (rhizosphere).