Abstract: Early warning and prevention of the harmful impact of alien species on ecosystems is afundamental requirement of the European Biodiversity Strategy and the EU Action Plan to 2010and Beyond. In the absence of reliable regional analyses however, the European states have beenunable to tackle this issue strategically. As part of the Europe response, a pan-European inventoryof invasive alien species has been developed through the DAISIE (Delivering Alien InvasiveInventories for Europe) project. The DAISIE database has collated information on over 11,000introduced species of fungi, plants, vertebrates, and invertebrates in Europe, and of more than50,000 records of introductions. The rate of invasion for most species groups has become morerapid over the last century and clear differences in pathways of introduction have been identified.Most invasive plants and associated invasive invertebrates arrive in Europe via horticulture andagriculture, most vertebrates are deliberately release or escape from captivity and marineinvasions are closely linked to shipping patterns. DAISIE has a key role within ongoingdevelopments to tackle invasive alien species in Europe and is potentially a model for othercontinents which currently have much less detailed information on their alien biota.