Report of the Euphresco project 2015-F-146 'Harmonized protocol for monitoring and detection of Xylella fastidiosa in its host plants and its vectors (PROMODE)'. The PROMODE project workplan was developed to achieve two goals: (i) to strengthten/build the capacity of the laboratories working on the diagnosis of plant pathogens and (ii) to improve the performance (such as reliability and sensitivity) of the diagnostic tests used for the detection and identification of X. fastidiosa in host plants and insect vectors. In order to avoid duplication of efforts, the PROMODE network had set relevant collaborations with the EU-funded consortia of POnTE (GA 635646) and XF-ACTORS (GA 727987), whose research activities were also focused on the same pathogen.