Proficiency test (PT) is a way in which the performance and competence of laboratories are evaluated  and assessed. In proficiency testing, standardized samples are prepared with known status regarding the presence of the target pathogen(s). These are sent out to participating laboratories that analyze them using their own methods, equipment and reagents, and send results back to the Organizer(s). The Organizer(s) analyzes the results and provides a report detailing all participants’ results in confidential manner together with actual sample status. The current proficiency test aimed to evaluate the performance (efficiency and accuracy) of laboratories involved in the diagnosis of Xylella fastidiosa by using molecular and serological methods. This interlaboratory comparison is part of the research activities on the implementation of surveillance and monitoring program for X. fastidiosa, within the framework of the following ongoing European projects: 
-  Euphresco project (2015-F-146) “Harmonized protocol for monitoring and detection of Xylella fastidiosa in its host plants and its vectors” 
- H2020 “POnTE – Pest Organisms Threatening Europe (635646)” 
- H2020 “XF-ACTORS - Xylella fastidiosa Active Containment Through a multidisciplinary-Oriented 
Research Strategy (727987)”.