With the rapid development of ethnicity and health as a field of sociological research, this paper seeks to re-evaluate the development of ideas around ethnicity, ‘race’ and culture and consider how they have been applied to the question of health. Ethnicity as a social characteristic is contingent on the situation in which it is manifest. The process of marking ‘other’ ethnic groups includes stereotyping and racialisation, a process through which ‘racial’ or ethnic differences predominate to the exclusion of a consideration of social, economic and power relations. In the British context, the history of empire and medicine's justification of racist treatment of enslaved and colonised people, is relevant to understanding how ethnic and cultural differences have come to be essentialised and pathologised. Immigration to Britain only became a mass phenomenon after World War II, with settlement patterns following employment opportunities and kinship alliances. The state has a longstanding history of ‘managing’ diversity, sometimes essentialising differences between groups, at other times tackling disadvantage and discrimination experiences through policy action. Sociologists of health were slow to study ethnicity, with initial research coming from tropical disease specialists. The tendency of medicine to pathologise minority cultures is explored through case studies of the approach to rickets and the assessment of health risks associated with consanguineous marriage. Anti-racist approaches have encouraged the consideration of discrimination against and socioeconomic position of minorities. The field has developed with work on nomenclature and the operationalisation of ethnic identity, necessary to study health inequalities between ethnic groups and paying due heed to the contribution of socioeconomic position and racism to group experiences. Research into chronic conditions with complex analysis of a number of distinct contributory variables has been published of late. However, the excessive focus on South Asians and the record of measuring, analysing, but not necessarily tackling health disadvantage, are problems that remain to be addressed.