Integrated modeling is a novel approach to couple knowledge and models from different disciplines and research fields and to use their potential in the strategic planning of water management at the river basin scale. The MOSDEW integrated regional model has been developed in the Neckar basin, a 14,000 km2 river catchment in South–West Germany as a model cascade of nine submodels covering large scale hydrology, groundwater flow, water demand, agricultural production, point and non-point pollution and chemical as well as biological water quality. The models are being tested and validated in the Neckar basin as well as in additional river basins in West Africa (Ouémé basin) and Central Asia (Chirchik–Ahangaran–Keles basin, CHAB) with contrasting ecological, hydrological and socio-economic boundary conditions. The transfer to the CHAB basin required changes in the submodel selection and integration structure due to the strong anthropogenic modifications of the flow regime in the downstream area. There, water is conveyed from the Chirchik river to other catchments and distributed in a complex channel system to satisfy the demand of competing water users (irrigation, urban water supply, energy production). In the Ouémé basin, the ecohydraulic model was not integrated due to lack of input data for ecological requirements of fish species whereas the groundwater flow model was not applicable to the predominant presence of aquifers in fractured rock. The model results obtained so far are promising with respect to their accuracy to be used in scenario simulations for the strategic basin wide planning of water management.