Early warning system on Introduced Species in Wallonia is a presence-only dataset aimed to deliver in real time the occurrence records of introduced species within Wallonia. Data are aggregated from various online recording systems that are maintenaid by the Département d'Étude du Milieu Naturel et Agricole (SPW-DEMNA). Among these encoding systems, we find OFFH (Observations Faune Flore Habitats), the main occurrence encoding platform for the department experts and partners. But also specific surveys on exotic species (e.g. on the Giant Hogweed) open to the general public and thus based on citizen participation. As this dataset aims to feed an alert system on exotic species, it also include non-validated data and attention should be paid to the validation status of the records! If you have any return or remark, please do not hesitate to contact the Department for further details. ...