The prevalence of dementia is predicted to increase significantly as the population ages and with no foreseeable cure options the burden of dementia will continue to grow. Early diagnosis provides many benefits, including timely access to appropriate support services and provision of tailored therapeutic interventions for people with dementia and their carers. Memory clinics are a key response to the need for specialist assessment and diagnosis of dementia. Multidisciplinary team memory clinics are considered the “gold standard”; however, such resource intensive clinics are likely unsustainable. The nurse-led memory clinic format may provide a primary care focused, diagnostic service for dementia that does not have the cost implications of multidisciplinary memory clinics but there is limited research using nurse practitioners. This study is exploring the potential of a nurse-led memory clinic as a primary health care approach to health promotion (brain health awareness), disease prevention (risk factor reduction) and early intervention (diagnosis and management of dementia). A realistic evaluation of a nurse practitioner-led memory clinic is described. Realistic evaluation is concerned not only with the outcomes of an intervention but also with the context and mechanisms of the intervention. We are using a mixed methods case study design to describe and evaluate the impact of the nurse practitioner-led memory clinic. The nurse practitioner in this study is an advanced practice aged care nurse who focuses on mental health, and dementia diagnosis, management and risk factor reduction. This study seeks to inform the development of an expanded scope role for nurse practitioners in assessment and referrals for dementia diagnosis. The heterogeneity of clients attending the nurse-led memory clinic will allow us to evaluate what works in the memory clinic, for whom, and under what circumstances, in what respects, and to what extent.