Following a request from the EU Commission, the Panel on Plant Health performed a pest categorisation of 17 viruses and viroids, herein called viruses, of Cydonia Mill., Malus Mill. and Pyrus L. determined as being either non-EU or of undetermined standing in a previous EFSA opinion. These viruses belong to different genera and are heterogeneous in their biology. They can be detected by available methods and are efficiently transmitted by vegetative propagation techniques, with plants for planting representing a major long-distance spread mechanism and, potentially, a major entry pathway. Depending on the viruses, additional pathway(s) can also be seed, pollen and/or vector transmission. Most of the viruses categorised here are known to infect only one of few related plant genera, but some of them have a wider host range, thus extending the possible entry pathways. Three viruses (apple necrotic mosaic virus, cherry rasp leaf virus, temperate fruit decay-associated virus) and one viroid (apple fruit crinkle viroid) satisfy all the criteria to be considered as Union quarantine pests. Five viruses (apple green crinkle-associated virus, blackberry chlorotic ringspot virus, eggplant mottled crinkle virus, tobacco ringspot virus and tomato ringspot virus) and one viroid (apple scar skin viroid), satisfy the criteria to be considered as Union quarantine pests with the possible exception of being absent from the EU territory or having a restricted presence and being under official control. The remaining six viruses (apple geminivirus, apple latent spherical virus, apple-associated luteovirus, Pyrus pyrifolia cryptic virus, Pyrus pyrifolia partitivirus 2 and Tulare apple mosaic virus) and one viroid (applehammerhead viroid) were not found to satisfy one or more of these criteria. The Panel highlights thatfor several viruses, especially those recently discovered, the categorisation is associated with high uncertainties mainly linked to the absence of data on biology and distribution. Since this opinion addresses specifically the non-EU viruses, in general these viruses do not meet the criteria assessed by EFSA to qualify as a potential Union regulated non-quarantine pests.