Jean-Paul Sartre, since his academic beginnings, has had a special interest in the subject of contingency; Well, in 1926, the French philosopher produced a work that revolves around this topic. This work on contingency was done in Leon Brunschvicg's class. These ideas were further developed and after Sartre made four different versions of the manuscript, changed the title of his work four times, and went through many corrections, the work was finished and published in novel form by the date of 1938, under the title de La nausea (Cf, Cohen-solal, 1990; Cabestan & Tomes, 2001). This idea of contingency will reappear in Being and Nothingness as the category that allows us to capture nothingness: "The contingency of the world appears, then, to human reality insofar as it has installed itself in nothingness to capture it" (Sartre , 1993, p.54). Now, what place does the notion of contingency occupy in Sartrean philosophy? What contributions does Nausea give to the development of Being and nothingness? Answering the following questions corresponds to the central interest of this article; For this, an analysis was made of the already mentioned work, La Nausea, and it was contrasted with some passages of Being and Nothingness.