It is important to constitute a detailed, easily understandable, and visually appealing database related to rail freight transportation for carrying out various analyses, making more effective operational plans, and finding solutions for many management problems. Hence, in this paper, the rail freight transportation in Turkey is analysed, giving a special emphasis on Geographic Information Systems (GIS). In order to carry out the study, at first, the origin and destination (O-D) matrices for 20 different kinds of commodities carried by the Turkish State Railways (TCDD) in the year 2000 were determined by using the statistical data provided by TCDD. Afterwards, the railway network was coded, and the O-D matrices obtained for these 20 different commodities were assigned onto this network based on an all-or-nothing assignment. Consequently, the commodity flows on the railway links resulting from assigning these matrices onto the railway network were found. Finally, these matrices and the commodity flows on the railway links were transferred into the GIS environment to enable the full range capability needed in this research. In other words, GIS were adopted for capture, storage, manipulation, and analysis of information related to the O-D matrices for different commodities transported by rail and commodity flows on railway links resulting from assigning these matrices onto the railway network. Consequently, this study places identification of the O-D matrices for various commodity types carried by rail and the commodity flows on railway links in a broader perspective by using GIS.