BACKGROUND: This paper defends the ethical and empirical significance of direct engagement with terminally ill children and adolescents in PPC research on health-related quality of life. Clinical trials and other forms of health research have resulted in tremendous progress for improving clinical outcomes among children and adolescents diagnosed with a life-threatening illness. Less attention has been paid, however, to engaging this patient population directly in studies aimed at optimizing health-related quality of life in PPC. Though not restricted to care at the end of life, PPC–and by extension PPC research–is in part dependent on recognizing the social complexities of death and dying and where health-related quality of life is a fundamental element. To explore these complexities in depth requires partnership with terminally ill children and adolescents, and acknowledgement of their active social and moral agency in research. DISCUSSION: Principles of pediatric research ethics, theoretical tenets of the "new sociology of the child(hood)," and human rights codified in the United Nations Convention on the Rights of the Child (UNCRC) underpin the position that a more engagement-centered approach is needed in PPC research. The ethics, sociologies and human rights of engagement will each be discussed as they relate to research with terminally ill children and adolescents in PPC. Qualitative method(ologies) presented in this paper, such as deliberative stakeholder consultations and phenomenology of practice can serve as meaningful vehicles for achieving i) participation among terminally ill children and adolescents; ii) evidence-bases for PPC best practices; and iii) fulfillment of research ethics principles. CONCLUSION: PPC research based on direct engagement with PPC patients better reflects their unique expertise and social epistemologies of terminal illness. Such an approach to research would strengthen both the ethical and methodological soundness of HRQoL inquiry in PPC.