Recent research from the United Kingdom (UK) has highlighted some of the differences in breast cancer presentations between women of different ethnic groups. Analysis of a large database showed that Black women of African or Caribbean heritage living in England and Wales are more likely to present with stage 3 or 4 cancer than White British women and less likely to have their cancer detected through screening. In many countries around the world, migrant and cultural minority groups experience social and economic disadvantage and this is reflected in their health outcomes. With world migration at record levels, it is timely to reflect on ethnic disparities and to consider how developed nations can care for their minority groups, which are increasing in number and diversity. These issues and challenges are discussed, using the UK's migrant population and Australia's Indigenous and migrant populations as case studies.