This in-depth case study explored whether one health care triad (a person with a diagnosis of dementia (PWD), their caregiver and primary care doctor) spoke about diagnosis in terms of the Common Sense-Self Regulation Model (CS-SRM) (H. Leventhal, et al., 1984) Illness Representations (IRs: identity, cause, timeline, consequences and the ability to cure or control the condition), and consider whether PWD IRs are understood by their caregiver and doctor. Each participant was asked a series of open questions, followed by questions prompting for each IR. The caregiver and doctor were interviewed about how PWD thought. All talked about IRs without prompting, with the exception of cause. Prompting for IRs elicited additional data. There were areas where participants shared IRs, but also areas of discrepancy which could have implications for health outcomes. IRs can provide a theoretical framework to elicit how people think about dementia, which could improve shared understandings in clinical practice.