Abstract: Deep excavation has an important impact on the deformation and safety of its adjacent buildings. However, very limited case histories on damage of adjacent buildings caused by a safely constructed deep excavation are available. Field monitoring is carried out during the construction of a 12 m-deep excavation for the foundation of a luxury complex building. The settlement deformations of 11 adjacent buildings caused by the deep excavation are analyzed. Also investigated are the settlement-related ground conditions, construction process of the deep excavation, lateral displacements of retaining structures, and foundation types of the adjacent buildings. It is shown that the ground conditions, namely a thick mucky silty clay containing silty sand, and dewatering are the underlying causes leading to damage of 6 buildings with settlements over 100 mm. An effective water-resisting curtain and dewatering measures are the key to control the influence of deep excavation on the adjacent buildings.