Flooding is a major risk, particularly in developing countries where the vulnerability of communities is exacerbated by low adaptive capacity and high dependence on their livelihoods. This research analyzes the vulnerability of human settlements to flood risk in the Couffo watershed in Benin. The collection work was carried out from 215 households following a reasoned choice in 20 villages throughout the Basin. In addition, 45 resource persons were made up of various categories of socio-professional actors. The Spatial Statistics Tools extensions of ArcGis 10.3 were used to characterize the density of human settlements and the determination of their vulnerabilities The results indicate that the basin is affected by rainfall (20% of localities) and river (nearly 68%) floods. Population expansion and agricultural activities have weakened ecosystems, increasing erosion and the filling of waterways, according to 98% of respondents. The very highrisk areas (Lalo, Tchito, Lon-Agonmey, Lobogo, Akodéha, Bopa) have a high density of establishments, and the high-to-very high-risk areas coincide with a medium to high density. Flooding also affects social cohesion. Although vulnerability varies, no village is spared, illustrating the difficult living conditions in the study area.