The aim of this study was to explore patients' and carers' preferences and expectations regarding their contribution to research in palliative care through the use of qualitative interviews. Data were collected in the context of two studies exploring the experiences of care of palliative care patients and carers. Both studies recorded the recruitment process, numbers of patients or carers accepting and declining, and the circumstances of interviews. Participants were asked about their motivation to participate in research. The data were analyzed by labeling patients' reflections on their motivations for participating in these studies and identifying themes. Analysis of the recruitment process revealed differential patterns in decline and acceptance of interviews by patients with different conditions and across settings. Among cancer patients, 21/51 declined; the proportion with other conditions that declined was small, and was 0/10 for patients with motor neuron disease. Motivation to participate in the studies was related to (1) altruism, (2) gratitude and concerns about care, (3) the need to have somebody to talk to, and (4) the need for information or access to services. Palliative care patients and carers were capable of deciding whether to participate in interviews and negotiating how they wanted this to happen. This strengthens the argument for patients' autonomy in deciding whether to participate in research. Patients and carers have different motivations for participation, reflecting the heterogeneity of the palliative care population. This suggests a need for ethics committees to reconsider their views and widen their perspectives on the involvement of palliative care patients and carers in research.