Purpose – The purpose of this paper is to set out key issues in the academic study of non-governmental organisation (NGO) accountability, and to introduce papers appearing in this special issue on NGO accountability. Design/methodology/approach – This is a discussion paper exploring key issues theoretically. Findings – The paper finds that there are many aspects of NGO accountability which should be explored in greater depth in future studies. Several other issues have been examined in the papers in this special issue of Accounting, Auditing & Accountability Journal. Research limitations/implications – There is a possibility that the issues explored in this paper, and the other papers in this special issue, will lead to a considerable growth in academic studies in this area. Practical implications – The paper is a contribution to the growing debate on NGO accountability. Originality/value – The paper sets an agenda for research into NGO accountability. © 2006, Emerald Group Publishing Limited