AbstractThis chapter focuses on the epidemiology and management of forest diseases caused by viruses. Information is given on different pathogen detection methods (biological indexing, electron microscopic observations, antibody-based methods, doublestranded RNA-analysis, molecular hybridization and PCR), infection biology, transmission (through mechanical method, insect, nematode and fungal vectors, seeds, water and soil), as well as on the management strategies and tactics. Tabulated data are provided on economically important viruses detected in forest and roadside trees, as well as on main characteristics of Cherry leaf roll virus, European mountain ash ringspot-associated virus and of the graft-transmissible chlorotic ringspots of Quercus robur associated with a virus.