Examining the pathways and causes of ethnic inequities in health is integral to devising effective interventions. Explanations set the scope for solutions. Understandings of ethnic health inequities are often situated in victim blaming and cultural deficit explanations, rather than in the root causes. For Indigenous populations, colonisation and racism are fundemental determinants of health inequities. Using a conceptual framework can support understanding of the fundamental causes of Indigenous health inequities. This article presents an Indigenous adaptation of the ‘Williams model’ for understanding the causes of racial/ethnic disparities in health. The Te Kupenga Hauora Māori modified model foregrounds colonisation as a critical determinant of health inequities, underpinning all levels from basic to surface causes. The modified model also attempts to reflect the dynamic interplay between causes at different levels, rather than a simple unidirectional relationship. We include the influence of worldviews/positioning as a cause and emphasise that privilege alongside racism plays a causative role in Indigenous health inequities. We also critique some of the limitations of this framework in reflecting the complex pathways of causation for ethnic health inequities, and indicate areas for further strengthening.