Municipal solid waste (MSW) is but one of many wastes. There are also construction and demolition debris, municipal sludge, combustion ash, mining and drilling debris, agricultural wastes, industrial-process wastes including some sludge, hazardous waste, and others. Altogether the United States alone produces about 10.1 billion tons (9.2 billion tonnes) of waste each year. MSW is barely 3% of that gigantic stream, but it is important: each of us is intimately associated with it. Its composition and amount is the result of our behavior. Moreover, if we move back one step, the businesses producing the products going into MSW generate much of those billions of pounds of waste. In Section I we ask why we generate so much waste. We examine municipal solid waste, what is in it, and why it is of concern. Section II looks at setting priorities in how we manage waste – the waste-management hierarchy (WMH). Pollution prevention is at the top of the WMH, but this section also examines reuse and recycling, incineration, and landfilling. Section III moves onto international MSW issues starting with wealthy societies, and examines the major problems that wastes pose in developing and impoverished societies. It ends with the example presented by the city of Curitiba, Brazil.