Transport of goods is of great importance in socio-economic life of societies. In Poland, where the power industry is based partially on bituminous coal extracted in mines of Upper Silesia, the transportation of coal is of great significance. The coal transportation acquires special importance in the corridor of the Odra River, where the Power Station Opole, Kogeneracja Wrocław, industrial complex of Power Station Dolna Odra, and numerous other industrial companies, that rely on such energy carrier are located. Location (intentional) of coal consumers, as well as historical determinants, created the chance of functioning of alternative transport systems: rail and inland waterborne ones. Intuitive interest in inland waterborne transportation as mass transportation that is cheaper and safer for natural environment, is the subject of present paper. Main objective is the presentation of the method for evaluation of so-called external costs in multimodal transportation of coal including the non-alternative rail transport between coal mines and the port of Gliwice, and inland waterborne transportation from the port of Gliwice to the consumers located by the Odra River.