Four viruses, hosta virus X potexvirus, tomato ringspot nepovirus, impatiens necrotic spot tospovirus and a tobravirus were identified in hostas (Hosta spp.) in the USA. Three unidentified isometric viruses were also found in hostas. Hosta virus X, a previously undescribed potexvirus, was the most frequently occurring virus in hostas, whose response to infection by this virus varied from immunity to severe mosaic and leaf desiccation. Tomato ringspot virus infection in hostas was associated with leaf mottling and chlorosis. Impatiens necrotic spot virus caused primary foliar lesions followed by latent infection. The tobravirus occurring in hosta was related serologically to both pea early-browning and tobacco rattle viruses, but was unusual in not being transmitted by mechanical inoculation to Nicotiana benthamiana or to N. clevelandii. Three unidentified isometric viruses, detected by electron microscopy and ds RNA analysis, were found in hostas with chlorotic ringspots, veinal necrosis and interveinal chlorosis. This is the first report identifying viruses in hostas in the USA.