This dissertation examines the presence of postmodern episteme in the Spanish American narrative discourse at the threshold of the 21st century with an emphasis on three writers: Carlos Fuentes Macias, Mario Vargas Llosa and Leonardo Padura Fuentes. Those authors are representative figures of this literary period in different regions, and they have written novels considered by the critique as postmodern. In their novels, this episteme is present in particular characteristics from this aesthetic and literary period, mostly the theoretical principles of Jean Francois Lyotard, Fredric Jameson, Jean Baudrillard, Umberto Eco, Michael Foucault, Paul Ricoeur, Brian McHale, Nicholas Zurbrugg, Ihab Hassan, Linda Hutcheon, Raymond Williams and Seymour Menton. All of these postmodern theories are reflected in the strategies and mechanisms used by these leading Latin American narrators and in the meaning that is conveyed through the novelistic discourse and how they point to the philosophical, aesthetical, and pragmatic cosmovision from this period. Chapter I functions as a theoretical approach to characteristics of Modernity, Postmodernity and their literary implications. Therefore, this study offers an outlook about what Postmodernity is from the sociological and anthropological points of view; what their key characteristics are; who the fundamental theorists are both in the international and Spanish American context; how Postmodernist's influence on art postulates a new aesthetic paradigm: the postmodern; and what formal, thematic and hermeneutic changes it has generated in the narrative genre. Finally, a critique and a personal stance in this polemic are offered. Chapters II, III and IV examine specifically the strategies and mechanisms used by these authors -- Carlos Fuentes Macias, Mario Vargas Llosa and Leonardo Padura -- to construct the postmodern narrative discourse in their respective novels -- La silla del Aguila, for Fuentes; La fiesta del chivo, for Vargas Llosa; and La novela de mi vida, for Padura --. These chapters disclose the presence of this episteme in the above mentioned works. The epilog concludes this study by pointing out the common characteristics of postmodernity present in each novel, and, in more general terms, the characteristics of this major Spanish American literary period in the narrative.