Biogenous waste (also biogenic or bio-waste) makes up a large proportion of municipal waste. This chapter begins with a definition of biogenous waste and a description of the quantities generated. It then addresses food waste as a major part of biogenous waste. A prerequisite for the treatment of this waste is its separate collection, which has been widely introduced in the EU member states. The processes and techniques used for composting and digestion, as the most relevant treatments for biogenous waste, are explained. The resulting compost and digestate are used as fertilisers and soil improvers, but their application may be limited by their heavy metal or nitrogen content.