The aim of this essay is to deepen the philosophical feminist discussion of the concepts sex and gender by doing a new reading of Simone de Beauvoir's The Second Sex. The analysis takes its point of departure from Judith Butler's "Sex and gender in Simone de Beauvoir's Second Sex" (1986) and Moira Gatens' "On Beauvoir and biology: a second look" (2003). This means that my overall inquiry is opened up by the question if, and in that case how, The Second Sex can be said to offer other interpretations than those presented by Butler and Gatens. I analyze Butler and Gatens' interpretations in terms of how their arguments are built up, in order to lay out the ground for my own, alternative reading. I formulate two questions, related to my initial analysis of Butler and Gatens: Does Beauvoir make a distinction between nature and culture which effects the understanding of the existent as a sexed, situated being? What implication does her existential-phenomenological perspective have for the image of the body and the creation of meaning? My reading suggests that Beauvoir's existential-phenomenological perspective can illuminate the concept of gender through pointing out how the beings of woman and man are rooted in, and develop out of, humanity's quest for being. This is a theme I find rather undeveloped in Butler and Gatens' articles. The sexed, bodily being of the subject is actualized as the source of meaning in this primary quest. Body and sexuality make up the expression of the existent, and therefore must be studied with regards to how meaning is created and carried out by them. I argue that Beauvoir's ideas of corporeality, disclosing of being and transcendence deepen the concept of gender in giving an ontological context to the beings of woman and man. I also claim that gender, in itself, is a useful concept in designating the dynamic, contingent and culturally dependent quality of these beings. This does not support, however, the view that Beauvoir makes a sex/gender distinction along the lines of a separation of nature and culture. The relevance of gender lies in its ability to highlight that the beings of woman and man manifest certain characters.