In France, research on ash dieback has begun in 2008 further to the first report of Hymenoscyphus pseudoalbidus in northeastern France. Then, the disease has quickly spread throughout the north of the country and has reached the north-west coast (Normandy) in 2012. The disease is now well established as severe dieback of Fraxinus excelsior and mortality has been observed in the north-east where the pathogen was firstly detected. We worked on the epidemiology of the disease, in particular on pathogenicity and genetic characterization in order to show that H. pseudoalbidus is an invasive pathogen. Our recent researches are focused on environmental factors affecting disease prevalence, impact of the pathogen on host population demography and dispersal ability using real-time PCR assays. From a breeding point of view, INRA aims at exploring the potential for resistance/tolerance in a network of 17 field trials that were installed between 1985 and 2009. These trials contain F. excelsior provenances from throughout Europe. Most of the material is organised as half-sib progenies thus allowing to access additive genetic variance estimates. A privately owned F. excelsior seed orchard located outside the chalara infested zone will also undergo laboratory assessment for resistance.