The elderly in palliative care are confronted with difficult decisions relating to treatments. The philosophy of palliative care, namely, including the patient and his/her family right away, leads the doctor to consult with the two parties involved when choosing a treatment. As no theoretical model allows us to understand how the decision-making process hinges on the trio (a capable elderly person, a family caregiver, and the doctor) in a context of palliative care, we propose one which was developed from three strategies of document analysis: theoretical synthesis, theoretical analysis, and theoretical derivation. According to our model, the decision-making process depends on individual factors influencing the decision of the participant, expectations and attitudes as to the role, the level of confidence amongst the parties involved, the manner in which they communicate with each other, their mutual understanding of the clinical and ethical issues, and, finally, their ability to cooperate.