This monograph covers 308 species of the butterfly subtribe Polyommatina. Included are 38 colour plates presenting collection specimens, including many type specimens and rare species. The text contains basic information about each taxon: by whom, when and where it was described, type locality. The structure of the genitalia of both males and females is described in detail, and differences from closely related species are discussed. The text also contains a section on distribution and taxonomic notes for most species. The highly artistic, yet scientifically accurate drawings of genitalia are depicted at a reasonable magnification, allowing important details of the structure to be clearly distinguished.