The Travellers in Ireland maintain a strong sense of ethnic identity, attachment and affiliation to their culture against rising assimilatory efforts by governments and policies. The Traveller community is at increased risk of problematic substance use, as a consequence of marginalisation, social exclusion and health disparity. The aim of the research was to explore the assimilation process within the context of Traveller habitus and heightened drug activity within Traveller communities, once virtually non-existent. Qualitative research using 12 gender specific focus groups with Travellers (n ¼ 57) was conducted; see Western Regional Drug Task Force report [Van Hout, M.C. 2009a. Substance misuse in the traveller community: a regional needs assessment. WRDTF report, Galway: Western Regional Drug Task Force, Series 2. ISBN 978-0-9561479-2-9; Van Hout, M.C. 2009b. Irish travellers and drug use -an exploratory study. Ethnicity and Inequalities in Health and Social Care 2 (1), 42-49; Van Hout, M.C. 2010. Travellers and substance use in Ireland-recommendations for drug and alcohol policy. Policy Paper. Drugs: education, prevention and policy (in press)]. This initial descriptive drugs research was plotted against a selective assimilation theoretical framework, using the concept of habitus in exploring the recent advent of drug activity within Traveller associational life. Traditional anti-drug Traveller culture is diminishing in potency, as families become fragmented and Traveller youth assimilate within educational settings, and over time one would question if drug use among Travellers will replicate or even exceed that of the 'settled' population, given the marginalisation and discrimination they experience. Young Travellers are experiencing contradictory drug norms and values in their assimilatory experiences of cultural and social change, with the sedentarist world presenting normative contexts for drug activity. The level of Traveller attachment to both Traveller and sedentarist values, and development of new action schemas in Traveller habitus will predict Traveller negotiation of the risk environment, as this ethnic group strives to retain their culture within the dominant sedentarist Irish society.