Emissions of N2O from main waste management processes are reviewed in this paper. Microbiological activities as the main processes for N2O production during the time of waste management are principally discussed with particular emphasis placed on the controlling factors of N2O generation from a standpoint of that these factors are noteworthy for the development of technologies to reduce N2O emission. A summary of the available data from both laboratory and field studies shows considerable spatial and temporal variability in N2O emissions because of its high susceptibility to environmental factors like waste composition, nitrogen and oxygen availabilities, water content and temperature. To overcome the uncertainty of N2O emission from waste management and reduce its emission, more detailed studies on effects of environmental factors are needed to simulate the procedures responsible for N2O production, consumption and transport in various treatment systems and establish specific models for each of the management system. Thorough understanding of the influencing mechanisms may enable us to optimize the operation parameters of waste management systems to control N2O emission.