Future floods in the Mediterranean region are influenced by the complex interactions between climate change and urbanization. This study investigates the projected impacts of these factors on peak discharge and flood volume in four medium-sized Mediterranean basins, using high-resolution weather and hydrological models. We analyze 32 heavy precipitation events under historical (end of 20st century) and future (end of 21st century, RCP 8.5) climate scenarios, incorporating projected urban expansion. Results indicate a significant decrease in accumulated precipitation, rainfall area, storm duration, and soil moisture, while rain rates increase. Hydrological simulations reveal contrasting trends: urbanization leads to a substantial increase in peak discharge and flood volume, particularly during low-magnitude events, due to increased impervious surfaces. Conversely, future rainfall scenarios show a decrease in hydrological response, attributed to reduced total rainfall and soil moisture. Combined climate and urban scenarios demonstrate that urbanization dominates, resulting in increased peak discharge despite reduced soil moisture. Spatial analysis highlights intra-basin variability, showing intensified peak discharge in streams of 1st and 2nd orders and in urbanized areas. The complex combined effects of urbanization and climate change underscore the need to adapt planning strategies to a changing climate while ensuring that climate adaptation measures account for future urbanization.