Groundwater quality in agricultural areas near urbanized regions in South China was studied. Most groundwater in the Pearl River Delta was found to be good for drinking. Factors like seawater intrusion and wastewater infiltration affected poor-quality groundwater in different types of aquifers. Overall, the majority of groundwater in these areas is suitable for drinking and farming, with poor-quality groundwater being a small issue. Protection of groundwater in agricultural lands should be a priority to maintain its quality.