Background: Emergency departments are chaotic environments in which complex, frail older persons living in the community and residential aged care facilities are sometimes subjected to prolonged emergency department lengths of stay, excessive tests and iatrogenic complications. Given the ageing population, the importance of providing appropriate, quality health care in the emergency department for this cohort is paramount. One possible solution, a nurse-led, physician-championed, emergency department gerontological intervention team, which provides frontload assessment, early collateral communication and appropriate discharge planning, has been developed. The aim of this Geriatric Emergency Department Intervention is to maximise the quality of care for this vulnerable cohort in a cost effective manner. Methods: The Geriatric Emergency Department Intervention research project consists of three interrelated studies within a program evaluation design. The research comprises of a structure, process and outcome framework to ascertain the overall utility of such a program. The first study is a pre-post comparison of the Geriatric Emergency Department Intervention in the emergency department, comparing the patient-level outcomes before and after service introduction using a quasi-experimental design with historical controls. The second study is a descriptive qualitative study of the structures and processes required for the operation of the Geriatric Emergency Department Intervention and clinician and patient satisfaction with service models. The third study is an economic evaluation of the Geriatric Emergency Department Intervention model of care. Discussion: There is a paucity of evidence in the literature to support the implementation of nurse-led teams in emergency departments designed to target frail older persons living in the community and residential aged care facilities. This is despite the high economic and patient morbidity and mortality experienced in these vulnerable cohorts. This research project will provide guidance related to the optimal structures and processes required to implement the model of care and the associated cost related outcomes.