Phys. chem. properties of refuse - derived fuel and 2 waste fractions from its prodn. (under sieve fraction with a size of 0-80 mm and ballast) were studied. Heat of combustion, calorific value, humidity and ash content as well as the content of C, H, S and CI were detd. The tested fractions showed high humidity, but the heat of combustion above 6 MJ/kg classified them as potential materials for further use.