The seismic nonlinear behaviour of earth dams is investigated by using a well-documented case study and employing advanced static and dynamic coupled-consolidation finite element analysis. The static part of the analysis considers the layered construction, reservoir impoundment and consolidation, whereas the dynamic part considers the response of the dam to two earthquakes of different magnitude, duration and frequency content. The results of the analysis are compared with the recorded response of the dam and exhibit a generally good agreement. The effects of the narrow canyon geometry, the reservoir impoundment and the elasto-plastic soil behaviour on the seismic dam behaviour are investigated. Finally the implications of the adopted constitutive modelling assumptions on the predicted response are discussed.