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Flooded rice fields are a large anthropogenic source of the greenhouse gas (GHG) methane (CH4). Aeration of the paddy field can reduce methane emissions and at the same time save water. Different forms of water saving techniques (WST), e.g. alternate wetting and drying (AWD) and midseason drainage (MSD), have been developed and disseminated. This article gives an overview on adoption of AWD in the Philippines and assesses prospects and constraints. It also explains the Clean Development Mechanism (CDM) methodology for rice production and analyses the mitigation potential of WST in the form of a literature review. The adoption rate of AWD strongly depends on the incentive for the farmer. While direct monetary incentives are limited to areas where saving water is directly linked to reduced costs (e.g. pump irrigation systems), indirect incentives (e.g. improved crop development) have not yet been scientifically assessed. The literature meta-analysis proves the great mitigation potential of WST. Methane emissions can be reduced by an average of 36.5% with a single drainage and by 43% with multiple aerations. Nitrous oxide emissions increase under all WST but this increase does not offset the reduction in CH4 emissions. This study also shows that the amount of GHG emissions can vary drastically between different regions. This poses a challenge for the transfer of mitigation strategies from one region to another.