In France, a ‘natural zone of ecological, faunistic or floristic value’ (Zone Naturelle d'Intérêt Écologique, Faunistique et Floristique - ZNIEFF) is a natural area, regionally known for its remarkable ecological characteristics. The ZNIEFF inventory is a naturalist and scientific survey programme launched in 1982 by the Ecology Ministry, with support from the French National Museum of Natural History (MNHN). This paper describes the ZNIEFF national dataset, which comprises 1,013,725 data for various animal (38%), plant (59%) and fungal (2%) species in terrestrial and marine zones (May 2020). A total of 19,842 sites throughout continental France. as well as in the overseas Departments and territories (Guadeloupe, Martinique, Mayotte, La Réunion, French Guiana, Saint-Martin, Saint-Barthélemy and Saint-Pierre-et-Miquelon), are included in the ZNIEFF dataset (May 2020). This dataset is now available in open access. All data were collected by skilled naturalists using professional protocols over almost 40 years. They consist mainly of observations of rare, threatened or endemic species, all validated by regional experts. Data are updated twice a year after national validation in both national (INPN-OpenObs) and global (GBIF) biodiversity web platforms. Some of the observed species, the so-called ‘trigger species’ or ‘determinant’ species, are of central interest for a site to be designated a ZNIEFF (zone of high ecological value). This concerns more than 35,000 taxa, mainly angiosperms, insects, fungi, birds and fish.