Oral poetry is one of the “non-book†declinations of literature, which are generally characterized by an investment of the author’s body and voice. Rhythm is a central element of this. Oral poetic performances presuppose the existence of a preparatory written text (except in the case of improvisation). They, therefore, constitute a privileged field to study the complex relationship between writing and orality. This research aims to study the construction of rhythms in a contemporary practice of oral poetry : slam. Born in the United States in the 1980s, this practice developed in Europe from open stages. Slam, intrinsically in motion, cannot be reduced to one form or genre. It is above all a stage performance governed by the following principle : an author has three minutes to say his/her own text, without accessories or music. Few studies have been carried out on slam, and most of them propose either an approach centered on the written text, or a sociological or psychoanalytic approach. This thesis aims to (1) define the rhythms in slam from internal voco-prosodic characteristics ; (2) analyse the respective contributions of the preparatory written text and of the oral performance in the making of rhythms. At the same time, I document the practice of slam in French-speaking Belgium. I propose an innovative approach, at the crossroads of a linguistics of spoken French and the literary theory of written poetry in order, on the one hand, to determine how rhythm is constructed within a largely unexplored poetic practice and, one the other hand, to develop a theoretical model contributing to the study of the relationship between oral and written discourse. ; La poésie orale est l’une des déclinaisons « hors livre » de la littérature, qui sont généralement caractérisées par un investissement du corps et de la voix des auteur·es. Le rythme en est un élément central. Les performances de poésie orale supposent l’existence d’un texte écrit préparatoire (sauf en cas d’improvisation). Elles ...