This critical examination of theories of reflexive modernity with respect to the new human genetics draws on a range of empirical studies and conceptual critiques. In it we explore the ways in which genetic knowledge and testing technologies offer new choices, construct new risks and generate public and professional ambivalence. We contrast this with the processes of ordering, reduction and control suffusing these developments. We argue that reductionism and determinism continue to infuse genetic theories and methods, that scientific and social progress are collapsed anew, and that certitude and surveillance remain powerful guiding principles. Within this context, the reflexive potential of individual choice, personal responsibility and risk estimation is seriously undermined. Indeed, in the case of the new human genetics, it seems that reflexive modernisation promotes, rather than curtails, a new modern/counter-modern eugenics. This occurs through the privatisation of lay ambivalence and professionals' successful institutional reflexivity. The paper concludes with a consideration of the implications of our reflections for sociology and participatory democracy more broadly.