It is indisputable that archives have become more relevant to critical studies. This fact has become especially important in the case of José Donoso since the publication of fragments of his diaries and letters in recent decades. However, little is known about its gestation. From the exploration of the preserved documentation and from the experience of working with formal and informal archives, the author demarcates in this article the main milestones in the formation of the Donoso archive, as well as new folds of biographical and scriptural density that emerge from it.