The increasing relevance of transnational governance for the regulation of crossborder economic relations in many public policy fields has given rise to debates about its legitimacy. This paper provides an introduction to normative and empirical approaches and suggests to bridge between them by exploring normative perspectives through the views and strategies of actors practically involved in transnational governance. Based on a synthesis of contributions from different fields of transnational governance, it is suggested that a perceived lack of fit between the regulators' legitimacy claims and the addressees' expectations, if expressed as protest and criticism by the latter, can lead transnational governance institutions to adjust to demands for more inclusiveness, expertise and procedural fairness. However, the rising level of expertise required from participants, stakeholders and publics to meet normative criteria for greater participation and procedural fairness creates new and yet unresolved problems.