Abstract: Maize is among the most important field crops in Europe. The only genetically modified (GM) crop that is cultivated on large scale in Europe is MON810 maize expressing the insecticidal Bacillus thuringiensis (Bt) protein Cry1Ab. One important part of the regulatory dossier of new GM crops is the environmental risk assessment, which identifies, characterizes, and assesses potential risks associated with the cultivation of the new crop. For the protection of biodiversity and the functioning of the agro-ecosystem, knowledge on the species present in the receiving environment of the new GM crop facilitates the formation of most relevant risk hypothesis. For European crop fields information on arthropods has been compiled in a publicly available database in a project commissioned by the European Food safety Authority (EFSA). The database contains 5’499 records of 1’679 arthropod species for maize. Most records of the functional group of herbivores are available for Lepidoptera (including the main maize pests Ostrinia nubilalis and Sesamia nonagrioides), Hemiptera (including aphids) and Coleoptera (including Diabrotica virgifera virgifera). Predator records are dominated by Coleoptera (mainly Carabidae, Staphylinidae, and Coccinellidae) and Araneae (mainly Linyphiidae). Decomposing species include Collembola, Coleoptera, Diptera, and Acarina. Parasitoids are mainly composed of Hymenoptera and Diptera (Tachinidae). For the environmental risk assessment of GM crops and other environmental stressors, the database can assist in selecting test species for laboratory studies, higher-tier studies, and post-market environmental monitoring.