This paper presents a numerical analysis of the influence of initial stress state on the response of deep excavation supported by retaining wall. Indeed, the influence of diaphragm wall installation prior to excavation works may affect the soil response and lateral wall deflection induced by excavation process. The first part of this paper gives a short review of the numerical methods aimed to reproduce the retaining wall installation. Numerical analysis of a deep excavation in two-dimensional and three-dimensional conditions is then performed according to the methods previously presented. In three-dimensional conditions, diaphragm wall installation is performed considering a sequence of panels, described by their number and length. Results of three-dimensional calculations confirm that stress state is disturbed by wall installation, which has a sensitive effect on the ground response induced by soil excavation. It is also noted that these results are not easily reproduced in two-dimensional conditions. Copyright © 2012 John Wiley & Sons, Ltd.