The assessment of autonomy in elderly people relies on various instruments that aim to evaluate and follow up patients, to measure the burden of care for the medical staff, or to properly distribute health budgets. In this article, we describe 3 clinical scales traditionally employed by gerontologists and specialists in geriatric rehabilitation. We intentionally left out generic scales such as the Barthel index and the Functional Independence Measure, which are well known by physiatrists. The Katz index is a scale of Activities of Daily Living, and the Lawton test is a scale of Instrumental Activities of Daily Living. We paid special attention to the AGGIR classification, which is the actual legal instrument for evaluating dependency in elderly in France, and whose first application is health resources management.