A number of impoverished people in developing countries engage as waste pickers who are scavenging recyclables from disposed solid waste along urban streets and in open-dumping waste disposal sites. Such waste pickers are taking a role of 3R (Reduce, Reuse and Recycle) practice in developing countries, where proper recognition of the waste pickers' activities is indispensable for effective solid waste management. In this presentation, the results of problem analysis for solid waste management in Buenos Aires is summarized in order to identify the needs and intention of waste pickers, and introduced an attempt of institutionalization of waste pickers' activities into the municipal solid waste management in Buenos Aires city. Based on these facts, appropriate municipal solid waste management system for developing countries is studied.