This article aims to expand both the analytical gaze of diplomacy studies and anthropological interests in the field of transnational think tanks, advocacy and policy advice. Drawing on ethnographic data from three such organisations, itinvestigates secrecy practices within transnational think tanks, focusing on how everyday practices undertaken in secrecy amount to discreet diplomatic efforts. In a variety of ways, secrecy is utilised as a resource in foreign relations and diplomacy, thereby aiming to leverage status and influence. Although outwardly striving for transparency, secrecy practices are thus vital in the striving of transnational think tanks to establish themselves as actors of consequence in foreign relations and diplomatic circles. It is argued that practices of secrecy are part and parcel of the power games played, in which all participants learn and master what to discuss and what not to display. These practices, however, also imply a challenge in terms of accountability and transparency.