peer reviewed ; The objective of this paper is to determine the environmental impact of rail freight transport in Belgium using the life cycle assessment (LCA) methodology. The study includes the assessment of diesel trains, electric trains and rail freight transport considering the Belgian traction mix. Moreover, a comparison of the environmental impacts of electric trains using the electricity supply mix of diferent European countries has been performed. The rail freight transport system has been divided into three sub-systems: rail transport operation, rail equipment and rail infrastructure. The system approach of the LCA methodology involves studying both the direct processes connected with the transport activity (e.g. energy consumption or direct emissions), as well as other necessary elements for rail transport such as energy production, rolling stock and railway infrastructure. A comprehensive study of the Belgian railway network has been performed, collecting country-specifc data on the construction, maintenance and disposal of infrastructure. Electric trains present a better environmental performance than diesel trains in Belgium. For example, the use of electric trains (using the Belgian electricity supply mix of 2012) rather than diesel trains represents a reduction of 26% of environmental impact on climate change. The electricity supply mix contributes signifcantly to the environmental performance of electric trains. As the use of electric trains increases in future, the energy split for the electricity generation will be more important in the environmental impacts of goods transport. The increased use of electric trains represents an opportunity to attain a more environmentally and energy-efcient rail freight transport system, especially when they are powered by sustainable electricity. ; Brain-Trains - TRanversal Assessment of Intermodal New Strategies