Ageing of the population in western societies and the rising costs of health and social care are refocusing health policy on health promotion and disability prevention among older people. However, efforts to identify at-risk groups of older people and to alter the trajectory of avoidable problems associated with ageing by early intervention or multidisciplinary case management have been largely unsuccessful. This paper argues that this failure arises from the dominance in primary care of a managerial perspective on health care for older people, and proposes instead the adoption of a clinical paradigm based on the concept of frailty. Frailty, in its simplest definition, is vulnerability to adverse outcomes. It is a dynamic concept that is different from disability and easy to overlook, but also easy to identify using heuristics (rules of thumb) and to measure using simple scales. Conceptually, frailty fits well with the biopsychosocial model of general practice, offers practitioners useful tools for patient care, and provides commissioners of health care with a clinical focus for targeting resources at an ageing population.