Schools and schooling have long provided a tempting site for the delivery of public health strategies that address and promote young people's current and future health. However, an emerging concern regarding the mobilisation of public health interventions within school settings has been the failure of school teachers to deliver such programs with fidelity. For educators, these notions of fidelity stand in stark contrast to the tenets of student-centred teaching. In seeking to explore these tensions further, this paper draws upon a collaborative health education project conducted with schools and teachers from Queensland, Australia.Findings from this project reveal the complexity associated with curriculum implementation in school settings, where diverse resources including timetable allocations and teacher expertise mitigate the achievement of program fidelity. In our efforts to explain the findings emerging from this project, we have drawn on the conceptual reference points of Basil Bernstein's theory of the pedagogic device to reveal the predictable misalignment of the health and education sectors' expected outcomes of school based health initiatives. In conclusion, we argue that our exploration of issues pertaining to fidelity demonstrates the need for health and education sectors alike to conduct their work according to a clear articulation of the realistic, educative role that schools can play in promoting healthy living.