This article introduces a tri-national research and development project which aims to develop indicators for the cross-sectoral and interdisciplinary educational task 'education for sustainable development' (ESD). These indicators are meant to help monitor the implementation of ESD efforts in schools and institutions of higher education and, potentially, may apply to educational monitoring reports. As these kinds of indicator-based reports address a variety of stakeholders, the article focuses on how these stakeholders are included in the process of developing a set of ESD indicators in the course of the project. Its empirical stages and intentions are therefore presented, as well as some of the project's main challenges and the ways of coping with them.