What impact will land use and climate change have on Spain's groundwater? This paper examines the potential implications of these changes on the five aquifers beneath the Upper Guadiana catchment. The research uses a physically based hydrological model to explore how various scenarios might affect groundwater recharge. This is a critical area in determining the downward flux of water. The model is integrated with a range of climate change scenarios derived from general circulation models. Aquifer replenishment is analyzed for the main four cover types, examining the implications for groundwater resources. These climate scenarios are then combined with a model of irrigated land use change. The results indicate that current climatic variability has a greater impact on groundwater recharge than several extreme climate change scenarios. Land use change has a more significant impact than climate change but is still relatively small at the catchment scale. This change may affect surface flows but has less impact on groundwater resources, addressing topics concerning environmental and regional studies.