This article looks at two processes that are affecting the characteristics of poverty in the city of Montevideo: the weakening of lower-skilled workers' attachments to the labour market and the growing concentration of such workers in neighbourhoods with a high density of poverty. While far from conclusive, the results suggest the advisability of further research into the relationship between changes in the social morphology of cities and the segmentation of their labour markets. If further research confirms both a tendency towards growing polarization in the spatial distribution of social classes in cities and the presence of feedback mechanisms reinforcing the social isolation of residents in the most disadvantaged neighbourhoods, it will be safe to say that these processes, if not effectively countered, will irreversibly widen the already excessive inequalities that affect large Latin American cities.