Some 30 different viruses have been reported infecting orchids in various regions of the world. Of those, Odontoglossum ringspot virus (ORSV) and Cymbidium mosaic virus (CyMV) are considered the most important ones due to their prevalence, worldwide occurrence and the severe symptoms they can induce in several orchid genera, often reducing their vigor, lowering flower quality and leading to economic losses. Mixed infections are quite common, because these viruses have similar biological and epidemiological characteristics and are frequently transmitted together.