In many developing countries, the informal recycling sector is responsible for reducing the amount of waste in landfills and supplying the needs of recycling industries. In the context of municipal solid waste (MSW) management, considering that developing countries aim to implement circular economy (CE) actions, it is essential to ensure the inclusion of waste pickers (catadores) in an adapted CE structure. This study analyzes the integration of recycling cooperatives in the formal management of municipal solid waste with recyclable potential (MSWRP) of a medium-sized municipality in Brazil, with the objective of ascertaining the contributions of cooperatives in an adapted CE structure and, at the same time, identifying a cooperative that can be used as a benchmarking option for other cooperatives, especially in relation to their organizational and operational practices. The results indicate that from this integration, cooperatives have legal responsibility in the management of MSWRP, resulting in the professionalization of its members and increasing their productivity. The results also revealed that the implementation of the CE in developing countries is, in a sense, conditioned to the performance of the informal sector in the recycling chain and, in addition, that the inclusion of cooperatives in the formal sector of MSWRP management can improve the rates of a municipality.