Flooding is a devastating and natural catastrophe to population, environment, and socioeconomic development globally. Floods occur frequently in Afghanistan, especially in Kabul River Basin. Many geographical techniques have been established in recent years to map, predict and model flood risks. This research investigates identification of flood-prone zones and development of mitigation measures in Kabul River Basin. First, in this research, GIS and MCDA methodology was applied to generate flood risk map. Also, AHP method was applied to determine the best weights to be assigned to the factors that influence risk of flooding. A flood risk map of KRB was produced using 10 conditioning criteria; soil, rainfall, lithology, LULC, TWI, NDVI, distance to stream channels, curvature, elevation, and slope. Based on the weighted overlay integration of GIS-AHP technique, KRB was grouped into four flood vulnerability zones; very low, low, high, and very high. Generated flood risk map indicates a good match with the flood risk areas and location of past floods in the basin over recent years. Second, 2D HEC-RAS model and flood frequency analysis were developed for different scenarios to simulate the flow of river and to develope mitigation measures with a 500- year return period in the main river of Kunar and the lower Kabul sub-basin. Manning's n values were used to calibrate HEC-RAS model, and past flood events applied for validation. Flood mitigation strategies, including river restoration, construction of dam, and reservoir improvement were proposed on the Kunar and lower Kabul sub-basin. Keywords: Flood Inundation Map, Hydraulic Modelling, ArcGIS-MCDA.