Diverse plant fossils have been reported from the Miocene deposit in the Lesvos Petrified Forest, Greece. Increasing record of fossil wood taxa provide significant understanding for exploring the fossil diversity and palaeoecological implications of this fossil wood forest. However, structurally preserved fossil plants bearing fungal remains are exceptionally rare in this region. Here, we report a new fossil wood Lesbosoxylon zourosii sp. nov. Zhu et Wang based on anatomically well-preserved fossil specimens from the Miocene Sigri Pyroclastic Formation in Lesvos, Greece. Anatomical analysis reveals key features, including axial and radial resin canals, abietinean radial pitting, pinoid cross-field pitting, and three distinct ray types. In addition, this investigation documents the presence of well-preserved fungal hyphae, and feeding traces within the wood host. This represents the first report of fungal remains associated with fossil wood in Greece. Paleoecologically, the fungal remains are tentatively interpreted as a kind of decay fungus, contributing to the decomposition of plant material. Lesbosoxylon zourosii sp. nov. not only further enriches the fossil diversity of the Lesvos Petrified Forest, but also provides new evidence for plant-fungal interaction in the Early Miocene terrestrial ecosystem of the East Mediterranean.