From 2014-2016 a series of studies were conducted in the Mekong Delta region of Vietnam to evaluate the impact of introducing Alternate Wetting and Drying (AWD) water management to the existing rice management package as a way to decrease greenhouse gas (GHG) emissions. Studies were conducted at two study sites for three planting seasons. Methane gas emissions averaged across locations and seasons was 13 t CO2 eq ha-1 for the conventionally managed fields. Adding AWD to the management package resulted in an average methane emission of 3.6 t CO2 eq ha-1. Nitrous oxide emissions were similar for both systems. Rice grain yields were nonsignificantly greater in the AWD treatment. Global Warming Potential (GWP) was significantly lower in the AWD fields when compared to the conventionally managed fields. These results demonstrate a significant reduction in GHG emissions can be achieved by adding the AWD treatment to existing recommendations. This translated into a significantly lower global warming potential for all locations and plantings.