Xylella fastidiosa is a phytopathogenic bacterium that can affect plants in key agricultural sectors: grapes, citrus, Prunus, olives, alfalfa, oak, maple, horticulture, forestry, etc. There are no curative measures against this bacterium, except for grubbing up and destroying the contaminated plants and controlling the insect vectors. X. fastidiosa was first detected in Europe in 2013 in Italy, and was detected in Corsica in July 2015. More recently, isolated outbreaks have been reported in a greenhouse in Germany and also in Spain (Balearic Islands and the Alicante region). Here is an update on the role of the ANSES Plant Health Laboratory in combating this bacterium.