Background: This study reports the process evaluation of the In-Dialogue conversation aid to facilitate shared decision-making with people with intellectual disabilities in the palliative phase. Methods: Training for In-Dialogue was evaluated by 53 support staff members through questionnaires. The use of In-Dialogue in four residential care facilities for frail people with mild to severe intellectual disabilities was evaluated with semi-structured interviews with five relatives, nine support staff and three people with intellectual disabilities. Results: Most participants considered the training helpful to apply shared decision-making. Sixty-three people with intellectual disabilities participated in In-Dialogue conversations. Almost all interviewees stated that these conversations provided additional insight into people's concerns and preferences. Involvement of people with profound intellectual disabilities and their relatives appeared to be challenging. Conclusion: Conversations about illness and the end of life appeared to be feasible with the In-Dialogue conversation aid and provided insight into people's experiences and preferences.