Organizations of recyclable waste pickers play an essential role in solid waste management. Their noticeable evolution in terms of organization and participation in public policy has not been sufficient when facing the challenges imposed by the recycling services market. In that sense, individual waste-picking enterprises have sought to articulate into cooperation networks with the goals of increasing their strength and survival capability. The present research work aimed, therefore, to analyze the tendency to sustainability of waste picker cooperation networks considering the dynamics of cooperation adopted by them. To that objective, research of a descriptive character was adopted, based on multiple case studies composed by networks coded 1, 2, and 3, all within the state of São Paulo, participants of the Cataforte III project and counting on different sizes, ages and management practices. Based on documentary analysis, semi-structured interviews and application of the Sustainability Index (BESEN et al., 2017), this work sought to understand and to identify the main characteristics of cooperation networks, to adapt the Sustainability Index to the reality of the networks, and to relate the result of its application to the presence or absence of cooperation dynamics in the aforementioned cases. From the case analyses it was possible to find relations between cooperation dynamics and the tendency to sustainability. In general, Index application results coincided with adopting practices that lead to cooperation categories. In particular, voluntary participation stands out, having shown to be essential in consolidating waste picker networks, allowing for a better performance in sustainability-related indicators. Although the literature points out the benefits brought by joint commercialization as the main positive effect of network articulation, this research has indicated that the advantages go beyond commercial issues. Exchange of knowledge, development of social capital and legal and administrative infrastructure provided by the network reflect positively in its members, rendering joint commercialization another possibility of strengthening enterprises on the recycling services market when facing the array of options provided by cooperation networks.