This article discusses children as contributors to sustainable ecological development. The aim of the article is to develop a framework for researching two questions: What are the prerequisites for children to become responsible environmentalists? What actual and potential influence do children have on their family’s consumption? Three theoretical perspectives are elaborated in relation to relevant empirical research: children as cosmopolitan actors and world citizens, children as ‘subjects of responsibilization’ in relation to the discourse on sustainable development and children as actors influencing family negotiations about consumption. The article concludes by suggesting methodological implications that follow from this framework.