This is the first in a short series that presents case study examples of the use of comprehensive geriatric assessment (CGA) in different clinical settings. CGA is a holistic assessment model, which is designed to determine a frail older person’s medical and mental health status, as well as functional, social and environmental issues. When applied by nurses, it can enable individualised planning for older people’s health, safety and wellbeing. This article presents the case of a patient who had been admitted to hospital as an emergency for a suspected exacerbation of chronic obstructive pulmonary disease and subsequently developed a severe episode of delirium. It explores how the use of CGA at the point of her admission would have provided the patient with a higher standard of care and may have prevented her delirium.