Problems arise when applying the current procedural conceptualization of decision-making capacity to paediatric healthcare: Its emphasis on content-neutrality and rational cognition as well as its implicit assumption that capacity is an ability that resides within a person jeopardizes children's position in decision-making. The purpose of the paper is to challenge this dominant account of capacity and provide an alternative for how capacity should be understood in paediatric care. First, the influence of developmental psychologist Jean Piaget upon the notion of capacity is discussed, followed by an examination of Vygostky's contextualist view on children's development, which emphasizes social interactions and learning for decision-making capacity. In drawing parallels between autonomy and capacity, substantive approaches to relational autonomy are presented that underline the importance of the content of a decision. The authors then provide a relational reconceptualization of capacity that leads the focus away from the individual to include important social others such as parents and physicians. Within this new approach, the outcome of adults' decision-making processes is accepted as a guiding factor for a good decision for the child. If the child makes a choice that is not approved by adults, the new conceptualization emphasizes mutual exchange and engagement by both parties.