Aims As conceptualized by Robert Park in 1928, the 'marginal man' occupies simultaneously an intermediate point between two distinct cultures that embody some level of contradictory normative expectations, behaviors and beliefs. This paper explores the influence of ageing and social change on the creation of marginality among injection drug users over age 50 who have been chronic heroin users since their youth. Design Our data are drawn from in-depth interviews with 40 (2 8 male and 12 female) not-in-drug-treatment, active injecting drug users between the ages of 18 and 68. Setting Our sample was recruited using street outreach as part of a larger, community-based study conducted from a converted storefront in a high crime, economically depressed neighborhood on the west side of Chicago. Findings As they aged, and under the pressures of social change, the older users whom we studied moved from center positioning in the illicit drug culture of their youth to the margins of a differing drug culture of today where they participate largely unseen by others. Nostalgic for the 'Old School' mores of the past, and unable to transcend or assimilate fully into the cultural practices and norms of the 'New', they respond to their predicament by embracing 'poise' in the face of loneliness, stress and fear of victimization. Conclusions Our respondents' experiences draw attention to the need to refine the field's theoretical and practical understandings of what it means to be marginal and its consequences for older drug users and people in general. The results also point to what happens when society changes but some of its members do not.