Interest in solid waste disposal has been growing since the early 1960s, when researchers emphasized the potential for solid waste to harbor pathogenic microorganisms. Since then, society has become more interested in the environmental impacts of solid waste treatment and disposal, and how biological processes are used to minimize these impacts. This new text provides a basic understanding of the unique microbial ecosystems associated with the decomposition of municipal solid waste (MSW). It addresses the challenges of sampling and assaying microbial activities in MSW and describes preferred methods. The decomposition of MSW under anaerobic conditions in landfills and digestors is described, as well as under aerobioconditions during composting. The Microbiology of Solid Wastes discusses the need to consider MSW as an integrated system of collection, recycling, treatment, and disposal. A better understanding of solid waste microbiology will contribute to safe and economical solid waste management. Microbiologists, environmental engineers, and solid waste managers will all find this a useful reference.