. (2015). Ophiostomatoid fungi and their roles in Quercus robur die-back in Tellermann forest, Russia. Silva Fennica vol. 49 no. 5 article id 1328. 16 p. Highlights• Dominant ophiostomatoid fungi associated with Q. robur in the post-outbreak region of oak die-back were investigated.• Ophiostoma quercus was the most commonly encountered fungus.• This is the first report of O. grandicarpum from Russia.• The results of preliminary pathogenicity experiments demonstrate that fungi investigated in this study are unlikely to play causal role in oak die-back Pathogenicity of these fungi was tested using artificial inoculations on Q. robur trees. The fungi were shown to be non-pathogenic and unlikely to play any role in oak die-back. These fungi are most likely only components in a complex of abiotic, biotic and anthropogenic factors that have contributed to a die-back of Quercus spp. in Russia.