This Catalogue Is A Supplement To The Author's Short-Title Catalogue of Eighteenth-Century Spanish Books in the British Library (1994). It makes available for the first time some 300 products of the popular press, a very significant collection hitherto largely unavailable to researchers. The term chapbook (in Spanish, Libros de Cordel) denotes cheaply produced tracts for sale to ordinary people. Sold by hawkers, who would often sing or recite the contents for the benefit of prospective buyers, they represent a vivid repository of popular culture. Usually a single printed sheet, folded several times, these chapbooks were often adorned by woodcuts. Many are exceptionally rare. Each entry is catalogued fully, and there are indexes of printers and booksellers, places of printing, and subjects and places referred to. Thirty plates have been chosen to illustrate the range of material in the British Library's collection.