This article considers the extent to which the English National Curriculum for science has influenced practice and learning outcomes, and briefly reviews the mechanisms through which this influence is exerted. It identifies and discusses three central issues for the review that is now in progress: the structure of the science curriculum; the purpose of science within the school curriculum; and the way in which curriculum content is specified and communicated. It argues that the conflicting demands of breadth and depth need to be more authoritatively resolved, so that students beginning upper secondary school courses in the sciences do so on a more equal footing. It explores the curriculum consequences of the tension between the role of school science in improving the "scientific literacy" of all young people and in providing a sound foundation for more advanced study for the important minority who so choose. Finally it explores the aspirations of the current review for a clear and succinct statement of curriculum content, arguing that clear communication of intended curriculum content requires that examples be provided showing how these might be operationalised, and for recognition of both the value and the limitations of evidence and theory to underpin decisions on sequencing of science curriculum content. (Contains 11 notes.)