An abandoned dump of the Novator coal and uranium mine (Intra-Sudetic Basin, Czech Republic) was partly subject to spontaneous combustion in 1959-1970. This makes it possible to compare the geochemical patterns of its unburnt and burnt parts. The distribution of trace elements in the unburnt part of the dump is controlled predominantly by the content of organic matter, sulfides (chalcopyrite, sphalerite, galena, and pyrite), silicates and carbonates. In the burnt part of the dump, however, their distribution is controlled predominantly by the content of silicates, phosphates and sulfates. Moreover, metals and metalloids occur in the form of oxides and oxidized alloys. Lead in the burnt material of the coal waste dump is bound predominantly to anglesite, Pb-oxosulfate, Pb-silicates and Pb-glass. Copper is present in tenorite and zinc is hosted predominantly by franklinite and hematite. The concentrations of many metals and metalloids, especially Zn, As, Se, Mo, Ag, Cd, Pb, Bi, Tl and U, are significantly higher in the burnt part of the dump than in the unburnt section. This can be explained by their mobilization and accumulation at the surface layer of the burnt part of the dump. The spatial distribution of geochemical data within the dumped substrate indicates, however, that the degree of enrichment of the burnt part of dump in volatile as well as nonvolatile elements is highly variable and corresponds to the spatial distribution of metals and metalloids in the adjacent unburnt parts of the dump. This suggests only local remobilization of metals and metalloids during spontaneous combustion. The leaching potential of trace elements present in the waste samples was determined using batch leaching tests. The concentrations of sulfates, F, Se, Cd, Hg and Pb in some samples of water leachates from unburnt as well as burnt materials exceed the leaching limit values for inert wastes according to the EU legislation. The concentration of U in water leachates from burnt samples reaches max. 0.4 mg.kg(-1). Coal wastes of the Novator mine were exposed to leaching and weathering over almost 50 years. Within this period, the soluble authigenic minerals that originated due to self-burning were already dissolved or transformed to less soluble species. However, the results of leaching tests indicate that the dumped material, both unburnt and burnt, may still represent a potential source of contamination for local streams. (C) 2017 Elsevier B.V. All rights reserved.