This paper investigates the effects of finite element model updating on nonlinear seismic response of arch dam-reservoir-foundation systems. The highest arch dam in Turkey named Berke is selected for the numerical and experimental applications. Firstly, 3D finite element model of Berke Dam was constituted using an ANSYS software. In the analytical modeling, arch dam-reservoir-foundation interaction is represented by Lagrangian approach. Then ambient vibration tests were conducted to dam for four days, and experimental dynamic characteristics were estimated using an Enhanced Frequency Domain Decomposition technique. Experimental characteristics are compared with those of analytical obtained by the linear finite element analysis of the coupled system. Good agreement between mode shapes is observed during this comparison, though natural frequencies disagree by 15-20%. The linear finite element model of Berke Dam was updated by adjusting the material properties of the dam and foundation. By introducing the Drucker-Prager damage criterion, the updated linear finite element model was extended into an onlinear model. Nonlinear seismic behavior of Berke Dam was determined considering the acceleration record of Adana-Ceyhan, Turkey, earthquake in 1998 that occurred near the arch dam region. It is highlighted that the finite element model updating provides a significant influence on the nonlinear seismic response of arch dams. (C) 2010 Elsevier B.V. All rights reserved.