Published for the first time by Editions Eschig in 1953, with a preface by the dedicatee Andres Segovia, the 12 Etudes de Villa-Lobos were actually born in Paris, many years earlier, probably in 1924, to be completed in October 1928. Upon its release, the collection was recognized as one of the masterpieces of its author, and, more broadly, repertoire for the guitar of the 20th century. Although often interpreted separately, these studies have been conceived as a coherent whole, and each of them is closely related to the one preceding or following it by a tonal logic. The 12 Etudes show the polyhedral richness of Villa-Lobos' multiple cultural influences, ranging from JS Bach's music to Chopin's romantic lyricism, to Brazilian traditional music, as much in its urban form as in his African and Amazonian descent, for the last studies. This critical edition is the result of a careful study of all manuscript sources, which has allowed a new and relevant reconstruction of the different facets of the genesis of the collection. Finally, the volume includes a number of variants proposed in the appendix, as well as a meticulous critical commentary.