Based on a bibliographic research, the present book aims to present two different ways of expression used by Jean-Paul Sartre – philosophy and literature – to develop his Existentialism. Through the exposure of the main ideas contained in his work "Being and Nothingness: an Essay on Phenomenological Ontology", the objective is articulate his philosophy with the characters presented in his literary works. Initiating with a brief biography of the philosopher, the text continues with an explanation of fundamental concepts for the understanding of his thought, in order to discuss how these concepts are reflected in his writing, such as in the theatrical play "The Flies", the novel "Nausea" and the short story "Intimacy". Aiming to contribute as a study resource for those interested in the work of Sartre, this book draws parallels between his philosophical work and his literary writings.