Master thesis deals with residual stresses and their influence on the behaviour of stiffened curved panels. The use of curved steel panels in bridge design has increased in the last twenty years due to their aesthetic and structural demands. Curved panels may be used as a transversally curved bottom flange of box girders. Due to their late application, there is lack of specifications in European standards, since they are neither flat nor fully cylindrical. Shell structures are highly sensitive to imperfections (geometric imperfections and residual stresses) and should be properly taken into account. According to EN 1993-1-5, which deals with flat panels, both types of imperfections may be replaced with so-called equivalent geometric imperfections. Considering that there are no design recommendations for curved panels, a large parametric study was performed in order to investigate the effect of residual stresses on the behavior of stiffened curved panels, together with other important geometric parameters, such as curvature, aspect ratio and plate slenderness. Firstly, a linear buckling analysis (LBA) was performed in order to get buckling modes that were later used as geometric imperfections in the nonlinear analysis (GMNIA). All numerical simulations were carried out using the finite element analysis software Abaqus. Finally, results were compared with existing requirements from standard EN 1993-1-5.