Objective: To learn how to configure a patient communication aid (PCA) to facilitate shared decision-making (SDM) about treatment for advanced cancer. Methods: The PCA consists of education about SDM, a question prompt list, and values clarification methods. Study 1. A first version was presented to 13 patients, 8 relatives and 14 bereaved relatives in interviews. Study 2. A second version was used by 18 patients in a pilot study. Patients and oncologists were interviewed, patients were surveyed, and consultations were audio-recorded. Results: Respondents reported that the aid facilitated patient control over information, raised choice awareness and promoted elaboration. Risks were identified, most importantly that the aid might upset patients. Also, some respondents reported that the PCA did not, or would not support decision making because they felt sufficiently competent, did not perceive a role for themselves, or did not perceive that the decision required elaboration. Conclusions: Opinions on the usefulness of the PCA varied. It was challenging to raise awareness about the presence of a choice, and to find a balance between comprehensive information and sensitivity. Practice implications: A future study should demonstrate whether the PCA can improve SDM, and whether this effect is stronger when oncologists receive training.