The provision of intensive care enables the lives of neonates, infants and children to be sustained or extended in circumstances previously regarded as impossible. However, as well as benefits, such care may confer burdens that resultingly frame continuation of certain interventions as futile, conferring more harm than or any, benefit. Subsequently, clinicians and families in the paediatric intensive care unit are often faced with decisions to withdraw, withhold or limit intensive care in order to act in the best interests of the child. An integral consideration in respect of these decisions is that futility is a concept that has to be contextualised for all those involved. Recent high-profile legal cases highlight the professional, clinical, legal and social conflicts that can arise when parents and clinicians have different interpretations of futility. In acknowledging the complexity of these conflicts for clinicians, this paper aims to support a better understanding of futility as an integral concept in such difficult and emotive decisions within professional practice. We utilise the concept of futility to frame how these decisions to withdraw or withhold certain invasive life-prolonging interventions are ethically and legally justifiable, even when they disagree or conflict with parental views. To support clinicians in understanding these decisions, we in part use the familiar bioethical framework of Principlism developed by Beauchamp and Childress. We suggest that understanding legal and ethical analysis of futility ultimately will help clinicians in approaching and reflecting on such decision-making.