This book covers the whole of Geometrid moths fauna of mainland Spain and Portugal incl. the Balearic Islands (Mallorca, Menorca & Ibiza). The book consists of the following chapters: Foreword; Preamble; Introduction: Family characters of the Geometridae, Systematics, Origins of the Iberian and Balearic Geometridae, Background and current knowledge, Methodology, Acknowledgements; Systematic part; Species of Geometridae whose presence in the Ibero-Balearic area is doubtful or needs confirmation; References; Genitalia plates; Colour plates. In the systematic part, the text for each species is divided into the following paragraphs: Wingspan; Diagnosis; Biology; Distribution; Comments. The photographed colour plates illustrate all species apart from a very few where it has not been possible to obtain material. Most species are illustrated in several specimens. The genitalia illustrations are line drawings and cover the species where the genitalias may be useful for the identification.The book is the first ever to cover the entire Iberian Geometrid fauna. It is a big step forward and a fine supplement to The Geometrid Moths of Europe, both for those with a special interest in Iberian Geometridae as for those with a more general interest in European species.