Abstract:Commercial forestry in Uruguay is mainly based on non-native Eucalyptus and Pinus plantations. Eucalyptus is the most planted genera and covers approximately 730,000 ha. Currently, forest products represent one of the top three exports of the country. Over the last two decades, the number of reported pests that threatens commercial plantations has increased regularly, not only due to accidental introductions of exotic pests but also because of host shift of native pests and diseases from the native forest to the exotic forestry species. Some of the recently introduced pathogens have dramatically impacted on eucalypt plantations. For instance, Teratosphaeria nubilosa, reported in 2007, has forced the replacement of Eucalyptus globulus with more resistant species. More recently, Teratosphaeria pseudoeucalypti, another introduced pathogen reported in 2014, has dispersed very fast all over the country affecting many eucalypt species. On the other hand, Austropuccinia psidii, the causal agent of myrtle rust, originally described from native Myrtaceae, has shifted to eucalypts and affects young plantations. Foliar bacterial blight, bacterial wilt and dieback, and root diseases also affect plantations with sporadic incidence through the years. In most cases, the use of resistant species and resistant planting stock is the most effective approach to mitigate the impact of diseases on commercial plantations. The increasing international commercial trade, that results in more opportunities for pathogens to move among distant areas and continents, requires reinforced national surveillance and quarantine regulations.