Until now, family caregivers have been involved very little in the processes of assessing the quality of care delivered to a hospitalized relative. This study is the second phase of a broader research project whose aim is to develop measurement scales intended for elderly patients and their caregivers on their perceptions of the quality of services delivered in Geriatric Assessment Units. More specifically, the goal of this phase of the research is to document the criteria that caregivers use to judge the quality of these services: these criteria should constitute the content of the measurement scale that is intended for them. Four focus groups, bringing together 21 caregivers, allowed for the identification of 31 criteria of quality. These criteria have been classified according to six dimensions of quality: information, communication, attitude of staff, technical quality, continuity, and physical resources. The study highlights the dual concerns of participants: the well-being of the patient and support for caregivers. It shows that caregivers consider themselves to be clients of geriatric services.