With over 55,000 species described worldwide and over 1,000 of these recorded in Britain and Ireland, the Staphylinidae represent one of the most species rich families in the animal kingdom. Illustrated keys are provided for the identification of the subfamilies of British Staphylinidae. Five subfamilies, Oxyporinae, Steninae, Euaesthetinae, Pseudopsinae, Paederinae, Staphylininae are covered in full in this volume.