ABSTRACT Policy-makers in industrialised countries have been implementing polices to create neighbourhoods with diverse populations in the hopes of increasing and ameliorating inter-ethnic relations. However, social networks seem to remain largely segregated. The composition of people’s social networks is traditionally explained by population compositions and subsequent meeting opportunities versus preferences for homophilious interaction. Little attention has been paid to the social construction behind these two factors. This study of Turkish and native Dutch individuals in two neighbourhoods in Rotterdam from a time-geographic perspective shows that path-dependency plays a large role in keeping social networks segregated. The social circles individuals engage in during their lives are linked together. Individuals are introduced to places, activities and people by their existing social networks, starting with their parents and siblings. As such, they are likely to roam in spaces dominated by people of their own ethnicity, which lessens the opportunity to meet people from other ethnic backgrounds. This role of people’s existing social networks in ethnic segregation has been overlooked in the integration debate so far.