This essay explores the concept of style in Gilles Deleuze’s Proust and Signs. While the concept of style in Deleuze’s thinking in general indeed has been the subject of some examination, his specific understanding of style in Proust and Signs has, until now, not been properly investigated. The book was first published in 1964, with a second part and a conclusion added in 1970 and 1976 respectively, which explored new themes in Proust’s novel. Here, the concept of style is approached through two main questions: How is the concept of style constituted in the two parts constituting Proust and Signs? What is its significance with regard to the theme of individuation central to Deleuze’s reading of Proust? The first chapter examines Deleuze’s concept of style in relation to Proust’s own thoughts about style. The second and the third chapter analyze and compare the relationship between style and the essence in the two parts of Proust and Signs respectively. Despite some differences in how the concept of style is presented in 1964, when the Search is seen from the viewpoint of the subject (or the apprentice), and in 1970, when it is seen from the viewpoint of the artwork, the essay argues that there is a kind of continuity in the concept of style, which is above all a matter of individuation. Through the subject’s divergent repetition of the essence’ singular and individuating difference, and through the artwork’s production of haecceities, the concept of style renders the subject of thought as something that is never pre-given, but created in, through and with the artwork.