The promotion of children's decision-making is one of the principles of health-promoting schools, and the empowerment of children means that they are enabled to influence their lifestyles and living conditions. The aim of this study was to find out the suggestions of Spanish school pupils in Year 3 and Year 6 of primary education to promote their own health and the health of the people closer to them, through their ideas about health. We analyse the discourse on health in the school environment from focus groups of primary school pupils aged around 8 and 12 of five schools in the town of Alicante (Spain). The groups were organized according to the type of school (public, private), the socioeconomic status of the neighbourhood (residential, working-class) and gender (single-sex, mixed groups) to ensure both the highest intergroup diversity and intra-group homogeneity. The findings show that primary school pupils have a wide and diverse notion of health. The application of the focus group technique has proved useful in eliciting information from groups of primary school pupils, and involving students in health-promoting programmes because it allows them to identify the social and interpersonal determinants of health. There is a firm basis to consider school pupils as health agents, particularly regarding interventions within the school environment itself. With the support of teachers, it is possible to train school pupils as community health agents, and increase their control over their own health.