For many centuries, composting has been used as a means of recycling organic matter back into the soil to improve soil structure and fertility. The composting process has received much attention in recent years because of pollution concerns and the search for environmentally-sound methods for treating animal waste. The pig industry faces increasing problems from waste production as intensive pig production increases and pig units become bigger. This paper reviews information on the use of composting for treating piggery waste as a means of addressing the environmental pollution concerns. Ways in which composting has been used for treating pig manure, pig carcasses and pig litter as well as factors influencing the composting process are discussed. Suggestions for possible future applications are also presented.