In recent decades, recourse to notions of human dignity has increased extensively within the field of bioethics. In particular, the notion has been utilised in arguments that seek to constrain a variety of biotechnological endeavours, examples of which include human cloning and transhumanism. In this regard, transhumanism is frequently described as an affront to human dignity in a manner that appears to be aimed at halting the possibility of further debate. The efficacy of the concept of human dignity has itself, (...) however, been questioned. Criticisms include its ambiguous nature and thus the lack of adequate definition by those who utilise it, its supposedly religious undertones as well as the fact that it may be used to argue for diametrically opposing positions within the same argument, due to the existence of distinct and conflicting interpretations. In this paper, I briefly discuss the aims of the transhumanist movement and explicate the concept of human dignity in order to assess one of the most renowned dignity arguments that has been lodged against transhumanism, namely, the argument of the bioconservative thinker Leon Kass. In addition, I discuss the counter-argument of the transhumanist Nick Bostrom. These findings have implications for the concept’s efficacy to adjudicate the complex ethical conundrums posed, not only by transhumanism, but in the bioethics arena in general. (shrink)