Background Schools play an important role in promoting the health of children. However, little consideration is often given to the influence that headteachers’ and school staff’s prior beliefs have on the implementation of public health interventions. This study examined primary school headteachers’ and school health co-ordinators’ views regarding child health in order to provide greater insights on the school’s perspective for those designing future school-based health interventions. Methods A qualitative study was conducted using 19 semi-structured interviews with headteachers, deputy headteachers and school health co-ordinators in the primary school setting. All transcripts were analysed using thematic analysis. Results Whilst many participants in this study believed good health was vital for learning, wide variance was evident regarding the perceived health of school pupils and the magnitude of responsibility schools should take in addressing child health behaviours. Although staff in this study acknowledged the importance of their role, many believed the responsibility placed upon schools for health promotion was becoming too much; suggesting health interventions need to better integrate school, parental and societal components. With mental health highlighted as an increasing priority in many schools, incorporating wellbeing outcomes into future school based health interventions is advocated to ensure a more holistic understanding of child health is gained. Conclusion Understanding the health beliefs of school staff when designing interventions is crucial as there appears to be a greater likelihood of interventions being successfully adopted if staff perceive a health issue as important among their pupils. An increased dependability on schools for addressing health was expressed by headteachers in this study, highlighting a need for better understanding of parental, child and key stakeholder perspectives on responsibility for child health. Without this understanding, there is potential for certain child health issues to be ignored.