Children from seven classes, representing the year groups in an English primary school, were interviewed in groups of three or four to find out their understanding and views on issues related to the environment and science. The large majority showed considerable interest and concern about environmental issues related to their experience and understanding, drawn from school and influences outside of the school, though they showed limitations and contradictions in their understanding of the issues. The children's understanding of science was mainly limited to their experience of the subject at school and few showed any understanding of the impact of science on society or the environment. Examples of children's cognitive and moral development of environmental issues are presented, including a model of the phases in the development, as identified from the interviews. The implications for teaching science and environmental education are discussed, including philosophical and historical analysis of modern and postmodern trends in science and science education as background to interpretation of the findings.