When caring for a child who is in pain in a palliative care setting, the extent and intensity of the physical components of pain represent only one of many important aspects that need to be considered. How does the child understand their pain? Are they afraid of the actual pain or the future pain? How do they interpret their disease? Can they control or cope with the pain? It is of fundamental importance not only to help the child to cope with their condition, but also to help them through the disease by building a trustworthy and interactive relationship between the patient, their family, and their peers. One must try to carefully monitor the child’s level of distress, their defence strategies, their coping strategies, and the attitudes and opportunities that they encounter in their environment (e.g. encouragement, active participation in activities). All of this takes place within a biopsychosocial and holistic model of care that ‘reflects modern society’s attempt to face up to the reality of death by introducing dying and bereavement into the midstream of life.’ It personalizes care by adopting a relationshipcentred approach and, with the collaboration of all caregivers, it humanizes care. In this chapter we first explore the history of pain in medicine and then develop our actual knowledge about pain. This will enable us to understand the main theories without neglecting two central questions, namely how to deal with paediatric pain and how to engage in a therapeutic relationship with a young patient who is in pain. Finally, we shall establish some guidelines for understanding and analysing the complaint of the child in palliative care.