Substantial scholarly attention has been given to the effectiveness and legitimacy of private forest governance, especially the Forest Stewardship Council (FSC). Research has suggested that such cooperation between forest corporations and ENGOs may develop shared norms for responsible forestry. At least initially, however, conflicts are likely to occur since these stakeholders are accountable to different constituencies.Yet there are comparatively few studies on how such conflicts have affected the development and legitimacy of forest certification on the national level, which is where conflicts must be managed. This study explores how stakeholders' search for accountability has influenced the legitimacy of forest certification schemes, drawing on developments in Sweden. The study relies on the theoretical foundations of governance, legitimacy and accountability, and on reports from forest corporations and ENGOs. The results show that these stakeholders have continuously disagreed on the input and output legitimacy of forest certification, though the positions have changed over time, eventually making ENGOs reject forest certification schemes. These repeated conflicts have been fuelled by the stakeholders' search for public reputational accountability and market accountability. In effect, the very meaning of the FSC label is today being questioned. Thereby forest certification in Sweden has, at least temporarily, left the suggested path to the evolution of shared norms. These results call for related studies on how to manage accountability issues and power relations in forest certification. Copyright © 2012 John Wiley & Sons, Ltd and ERP Environment.