This monograph of the Fauna Ibérica Series is devoted to the five families (Papilionidae, Hesperiidae, Pieridae, Riodinidae, Lycaenidae and Nymphalidae) that are grouped in the superfamily Papilionoidea, the group of Lepidoptera widely known as the butterflies, of the Iberian Peninsula and the Balearic Islands. The authors have made an effort to compile the most relevant information on each species as well as the biological information which refers specifically to the Ibero-Balearic region: taxonomic position, geographic distribution, life history, ecology and phenology, parasitoids (or other natural enemies) and the current conservation status. These details are supported by an extensive bibliography. The descriptions, dichotomic keys and illustrations will facilitate the species identification. To assist this last purpose the volume includes a collection of colour plates to illustrate the adults of the almost 230 Ibero-Balearic species. The final part of the volume consists of a thorough, detailed nomenclatorial list of the taxa represented in the study area. The making of such compilation was remarkably complex given the numerous formal names that have eventually been applied to some of the studied taxa.