INTRODUCTION: There is significant international interest in the economic impacts of persistent inequities in morbidity and mortality. However, very few studies have quantified the costs associated with unfair and preventable ethnic/racial inequities in health. The proposed study will investigate inequities in health between the indigenous Māori and non-Māori adult population in New Zealand (15 years and older) and estimate the economic costs associated with these differences. METHODS AND ANALYSIS: The study will use national collections data that is held by government agencies in New Zealand including hospitalisations, mortality, outpatient consultations, laboratory and pharmaceutical claims, and accident compensation claims. Epidemiological methods will be used to calculate prevalences for Māori and non-Māori, by age-group, gender and socioeconomic deprivation (New Zealand Deprivation Index) where possible. Rates of 'potentially avoidable' hospitalisations and mortality as well as 'excess or under' utilisation of healthcare will be calculated as the difference between the actual rate and that expected if Māori were to have the same rates as non-Māori. A prevalence-based cost-of-illness approach will be used to estimate health inequities and the costs associated with treatment, as well as other financial and non-financial costs (such as years of life lost) over the person's lifetime. ETHICS AND DISSEMINATION: This analysis has been approved by the University of Auckland Human Participants Research Committee (Ref: 018621). Dissemination of findings will occur via published peer-reviewed articles, presentations to academic, policy and community-based stakeholder groups and via social media.