Public engagement in policy making is on mechanism used in an effort to improve the legitimacy of policy decisions surrounding ethically contentious health policy or medical technologies. Citizens’ trust in the process and in the medical, science and democratic institutions surrounding the policy is vital to the success of efforts to engage publics in deliberative processes. This paper explores the nature and role of trust in deliberative democracy, as well as effects of misplaced and abused trust on the legitimacy of specific policies and the overall project of inclusive participation of citizens in public policy deliberation.