Abstract Background Frailty is a significant determinant of health care utilisation and associated costs, both of which also increase with proximity to death. What is not known is how the relationships between frailty, proximity to death, hospital use and costs develop in a population aged 85 years and over. Methods This study used data from a prospective observational cohort, the Newcastle 85+ Study, linked with hospital episode statistics and death registrations. Using the Rockwood frailty index (cut off <0.25), we analysed the relationship between frailty and mortality, proximity to death, hospital use and hospital costs over 2, 5 and 7 years using descriptive statistics, Kaplan–Meier survival curves, Cox’s proportional hazards and negative binomial regression models. Results Baseline frailty was associated with a more than two-fold increased risk of mortality after 7 years, compared to people who were non-frail. Participants classified as frail spent more time in hospital over 7 years than the non-frail, but this difference declined over time. Baseline frailty was not associated with increased time spent in hospital during the last 90 days of life. Conclusion Evidence continues to accrue on the impact of frailty on emergency health care use. Hospital and community services need to adapt to meet the challenge of introducing new proactive and preventative approaches, designed to achieve benefits in clinical and/or cost effectiveness of frailty management.