General consensus exists concerning the relevance of networks and space in poverty situations, despite a considerable dispute on the prominence of each element. While social-support and poverty debates highlight the joint importance of space and networks, the research agenda on contemporary communities suggests that networks have recently started replacing space in social integration. These debates mainly consider networks and ties normatively and are restricted to the global North, hampering the formulation of comparative interpretations and more theoretical conclusions. This article discusses the relationship between space, sociability and poverty, based on research results on networks of poor individuals in two major Brazilian metropolises—Salvador and São Paulo. Research indicates the existence of great heterogeneity in the networks of poor individuals, although with substantial differences, on average, to middle-class individuals. Certain types of networks and sociability are systematically associated with better living conditions, employment and income. Additionally, network mobilization by individuals presents important regularities associated with social mechanisms, understood as regular patterns that trigger or cause certain results. These mechanisms explain to a great extent the heterogeneity of networks, and mediate the individual’s access to opportunities and everyday assistance. They therefore contribute decisively to the production (and reproduction) of urban poverty.