"The world as will and representation" is undoubtedly the top work of the German philosopher Arthur Schopenhauer. Originally published in 1819, it was revised and augmented several times until its final version, published forty years later, one before the author died. In it, the German thinker developed and compended a whole philosophical corpus and a living ethic starting from the main idea that being is will and its phenomenological expression is representation. Although his success and influence came late to the author, no one can doubt today the capital importance that this work had in contemporary Western thought, both in the field of philosophy, as in the field of arts or literature. The present edition reproduces the German publication of 1859, gathering, for the first time in Castilian, all the books, complements and appendices in a single volume in pocket format. Its translation, carefully reviewed by specialists, offers the text seamless, in its own context and annotation to be understood in its original purity and complexity.