Results are presented after four years of investigations concerning fungi isolated from above-ground parts of Quercus robur trees. 33 species of fungi were identified on the above-ground parts of Quercus robur. On trunk of oak trees 19 fungi species were found of which 8 species were isolated from bark and 3 from the sapwood. 15 and 16 species were isolated from dying branches and twigs respectively. Fungi established on leaves belonged to 9 species. Pathogenicity test was carried out with the following fungi: Amphicytostroma quercinum, Ceratocystis fimbriata, Ceratocystis moniliformis, Cytospora intermedia, Diplodia mutila, Fusarum solani, Fusicoccum quercus, Phomopsis quercella and Tubakia dryina. Dying of shoot of Quercus robur seedlings growing in sufficient soil humidity caused by Fusicoccum quercus.
