We aimed to obtain a greater understanding of the characteristics of social relations and experiences of social isolation among homeless people, substance users and other socially marginalized users of shelters and drop-in centres in Denmark. Based on in-depth interviews with 46 shelter/centre users, we created a typology of five groups: the socially related and content, the satisfied loners, the socially related but lonely, the socially isolated and the in-betweens. The characteristics of the groups did not seem related to interviewees’ degree of social marginalization. Professionals played a pivotal role, providing social support and help to improve interviewees’ life circumstances. The findings provide insight into the social lives of shelter/centre users that is useful for developing initiatives to improve their social wellbeing.