This master thesis is an in-depth study of Heidegger’s notions of death and authenticity in Being and Time. Heidegger’s existential notion of death is by many commentators considered to be radically different from the traditional metaphysical conception of death as the end of life. Disputing this view, I argue that Heidegger’s notion of death is a composite between the existential conception of being-towards-death, and the metaphysical conception of death as the end of life. There is a growing interest for the idea that Heidegger’s notion of authenticity is a descriptive, ontological foundation for a possible ethics. The notion of authenticity is too vacuous to have any ethical content. For authentic Dasein to become ethical Dasein, certain modifications of the existential web must be carried out. To establish the link between authenticity and ethics, I argue that the ontological status of das Man must be refuted, and that the temporal ecstasie of falling into the present must be understood differently as a movement of transcendence. The most important theoretical purpose of this thesis is to question the possibility of eliminating metaphysics. I argue that Heidegger’s notion of death is metaphysical in accordance with his own understanding of the term, thereby trying to show that certain phenomena –and most prominently death - are metaphysically constituted.