This article describes the Universal Education Foundation's (UEF) activities to create research tools and methodologies that capture the voices of children concerning their perceptions of the effect of the school learning environment on their well-being. UEF defines well-being as the realisation of one's physical, emotional, mental, social and spiritual potential. The "Voice of Children (VOC)" toolkit includes a survey and techniques to conduct focus groups as ways for young people to share their views. Young people participated in the development of the pilot instruments and, perhaps more importantly, they are involved as agents of change, presenting the findings through advocacy events to those who make decisions about policies and programmes that can have a positive impact on well-being. While UEF will be examining the effects of many learning environments--school, information and communications technologies (ICT) and media, and health care settings--this article focuses on the school as one learning environment. Methods to create Version One of the "Voice of Children" ("VOC1") and preliminary findings from the initial pilot in Palestine are described. Steps taken to revise the instruments and create Version Two for Wales ("VOC2") are discussed. UEF's definition of well-being and its sub-components, background research and theoretical framework, hypotheses and structure of the survey are reviewed. The overarching hypothesis is that learning environments--in this case the school--affect various aspects of young people's well-being, both overall and in its sub-components.