Groundwater is an important source of water for irrigation and domestic use in Cambodia. However, there is a need to better understand the groundwater resources to ensure sustainable use. A groundwater resource assessment for Cambodia would identify high potential areas for development, sustainable extraction limits, recharge processes, interactions with surface water, and water quality issues. Previous studies have provided some insights but a comprehensive assessment is still needed. Such an assessment could help maximize benefits from groundwater while avoiding overuse and environmental impacts.