Purpose – This paper sets the scene for this special issue by synthesising the vast array of literature on performance measurement to examine what constitutes performance measurement, and why it is important for the Third Sector. It also analyses key issues of performance measurement and introduces the papers that comprise this special issue of Qualitative Research in Accounting and Management. Design/methodology/approach – This paper takes the form of a literature review. The authors draw on extensive research on performance measurement from a diverse range of disciplines to identify and explore key definitions, opportunities and challenges with performance measurement in the Third Sector. Findings – Economic/Financial efficiency approaches, Programme Theories, Strategic and Participatory Approaches all present opportunities and challenges when measuring performance in the Third Sector. The papers in this Special Issue demonstrate the manner in which different organisations have dealt with these. Research implications - This special issue of Qualitative Research in Accounting and Management aims to stimulate qualitative research into performance measurement frameworks within the Third Sector both inside organizations and to their external stakeholders (supporters, clients and the general public). Practical implications- Those charged with governance and management in Third Sector Organisations (TSOs) will seek to use appropriate approaches to measuring and managing performance in order to learn and to discharge accountability. The different aspects of performance measurement will also be of interest to funders, donors, and those who seek accountability from TSOs.