This study examines the effect of corrosion on reinforced concrete structural elements of a bridge overpass in seismic affected areas. Starting from a literature review to identify the existing deteriorating models, a case study is selected to perform seismic analyses. It allows to assess the structural response at different levels of reinforced concrete degradation due to corrosion. The selected case study is a frequently used structural system with several existing examples in critical infrastructures all around the world. Consequently, an in-depth analysis of the degradation of this type of system, with the identification of the most appropriate time for restoration and the possible retrofitting strategies may be of interest.