Timely assessment, retrofitting (or replacement) of bridges has become an urgent matter due to their deteriorating conditions, the rise in traffic load demand and seismic code requirements, as demonstrated by recent failures observed worldwide. Various retrofitting solutions exist to enhance the seismic capacity in accordance with code-based requirements, but selecting the most appropriate one(s) should address not only structural criteria, as traditionally done, but rather carried out in an integrated manner. The selection should be based on diverse evaluation criteria, such as economic costs, social impacts, technical requirements, and environmental considerations, targeting sustainability. This study proposes a framework that accounts for different variables, among which the often-overlooked environmental impacts (EI), to support decision-making in bridge retrofitting. The seismic response of a case-study bridge located in Italy is investigated, evaluating both its as-built condition and four retrofitted configurations under two seismic hazard levels. The retrofitting strategies, designed as per standard engineering practice, are assessed through non-linear dynamic analyses to estimate their seismic performance and the expected direct economic losses with a component-based approach. Additional variables of different natures are also assessed; specifically, the EIs are evaluated through an environmentally extended input-output life cycle assessment (EEIO-LCA). Finally, the retrofit alternatives are compared using multiple decision matrices within a multi-criteria framework that incorporates 12 decision variables. The results show that adding EI as a decision variable in the decision-making process greatly affects how retrofit options are ranked. The proposed framework can support decision-making processes for engineers and stakeholders involved in identifying and selecting the retrofit strategies of existing bridges that best fit their objectives