The first part of this book presents the latest list of Austrian formicid fauna. Besides the distribution of species across the provinces, ecological ratings are cited, additionally. Currently, 31 genera and 133 free-living species are known and, additionally, 10 are recorded only inside buildings. Further, records of seven species remain questionable. Since all taxonomic changes of recent years are incorporated, the checklist sets a new reference for further studies on the regional ant fauna. The second part presents the oribatid mite fauna (moss- or beetle mites) of Austria. Their representatives belong to 198 genera and 79 families. For the first time the checklist takes into account potential 'species inquirendae', not clearly definable species, and species to be described, adding up to 623 valid taxa (606 species and 17 subspecies or 'formae', respectively). Thereof, records of 26 species represent new records for Austria. The knowledge of the oribatid mite fauna shows great regional differences and future studies will without doubt further increase the number of species existing in Austria.