Most diseases caused by Xylella fastidiosa have been reported from North and South America. However, since 2013, widespread X. fastidiosa infections have been reported in Apulia region of southern Italy and were associated with a devastating olive disease called olive quick decline syndrome (OQDS). Localized epidemic incidence called for urgent emergency measures and surveillance programs which resulted in detection of this bacterium elsewhere in the EU, namely, Corsica and mainland France, Balearic Islands and mainland Spain. From investigations carried out, different scenarios have emerged with regard to spread and suggested that several independent introductions occured in Europe in the past years. This was indirectly confirmed by numerous interceptions of infected consignments during intensified inspections at ports of entry. The EU outbreaks have been associated with a long list of susceptible species, including several hitherto undescribed hosts and associated to new X. fastidiosa strains. The rapid spread of X. fastidiosa has highlighted the serious threat the bacterium poses to the EU and Mediterranean agricultural industries. The current epidemic in southern Italy is an example of the pathogen’s destructive impact. Harmonized and coordinated EU research programs are underway to gain knowledge on the complex interactions of this pathogen under the EU conditions with the goal being to improve tools for early detection and control.