A novel height-retrieval method of individual urban structure from high-resolution (HR) synthetic aperture radar (SAR) images is presented based on the geometric property of the double-bounce contribution. The double-bounce contributions caused by the interaction of the visible walls and the surrounding ground are the key features of urban structure. Their scattering distributions and geometric properties are analyzed, a set of geometric models is built, and then a building-height retrieval approach based on these models is proposed. An analysis of the sensitiveness of the height retrieval to errors on the sensor system, building, and measured parameters is performed. The validity and superiority of the proposed approach are demonstrated by four simulation examples, two real very high-resolution MiniSAR examples, and four real HR TerraSAR-X examples.