Survey research of ethnic minorities in the 1960s brought the reality of ethnic and racial discrimination to the forefront of the national debate, playing a key role in anti-discrimination legislation in 1968. Despite legislation, ethnic and racial discrimination and harassment continues to be a feature of British Society, although this has declined against some groups and intensified against others. Not only does this violate the principle of a fair and equal society, it also has palpable adverse impacts on health, particularly mental health. The last comprehensive evidence of harassment was collected in 1994 and since then there is little statistical evidence about the prevalence of harassment and its impact on the health of ethnic minorities in Britain. This research uses a new, large-scale data source, Understanding Society, on minorities in Britain to investigate the current prevalence and type of ethnic harassment and its relationship to mental health and health behaviours such as smoking, drinking and physical activity. Since 2009, Understanding Society has been interviewing around 51,000 adults, including 10,000 ethnic minorities. The large sample size of the Understanding Society database allows us to look at who experiences harassment, where harassment is most likely, and what kind of harassment is most common. For instance, we will investigate how gender, age and education level intersect to produce particular vulnerabilities to both verbal and physical abuse as well as avoidance or feeling unsafe. We will determine in which locations people are more likely to experience harassment: in the street, on public transport, at the workplace? How might these differ in areas of low or high ethnic concentration? Because Understanding Society asks the same individuals about harassment repeatedly over time, we can examine not only one off experiences but also find to what extent people report persistent harassment. After establishing new benchmark estimates of harassment in the UK, we will go on to test for the impact of harassment on mental health and health behaviours. It is well known that those who experience harassment are more likely to have poor mental health, and that those stressed by harassment may turn to unhealthy coping behaviours such as drinking or tobacco use. However, it is difficult to establish causality, because individuals who experience harassment may also have personality traits or underlying proclivities which also lead them to have poor mental health or worse health behaviours. Fortunately, Understanding Society will enable us to establish time-order reasoning and to use statistical techniques which allow us to better establish causality in these relationships. Moreover, we can also investigate to which extent family relationships, friendships, presence of others of the same ethnic group in the neighbourhood and sense of belonging and identity protects minorities experiencing harassment from worsening mental health and health behaviours. Having repeated observations across time also enables us to examine whether any negative effects of harassment dissipate over time or if repeated experiences are more stressful than one off incidences. This research will have direct relevance to those who work with minority communities such as local governments and local services, as well as policy makers concerned with health and health equality. To make best use of the research we will meet frequently with a policy-orientated advisory group who will help refine our research questions and disseminate our findings to those governmental and third party organisations that will benefit from it, and develop a platform for research co-production to support a better, shared understanding.