In the last twenty years, globalization has fostered a progressive fragmentation of production, making transport and logistics a strategic field. Until now, road has played the lion part in European transport system, leading to a modal unbalancing. This has produced an increase in negative externalities and variable cost, questioning this solution for inland connections. The European Union indicates a modal shift in favor of sea-rail transport as a possible solution. Therefore, quality and efficiency of sea and rail services, to be competitive, should be the same of road solution. Notwithstanding general acceptance of sea-rail advantages, this solution is not common in European markets, in the case of Italy it is still rare and even ignored by public institutions and academia. This paper aims at studying sea-rail intermodal transport in Ro-Ro market and assessing the competitiveness of Trieste port in the European scenario. The result is achieved through a performance index estimation, based on the principle components analysis (PCA), that ranks the relative position of each Ro-Ro-Rail seaport. Trieste case study is reviewed also to learn from its success and to find critical factors for sea-rail implementation projects in the Italian and European context.