Raman microspectroscopy of organic matter, vitrinite reflectance and fluid inclusion data were used to reconstruct the thermal history in the lower Carboniferous accretionary prism of the Culm Basin in the Nízký Jeseník Mts. (NE Bohemian Massif). The model involves the Variscan (mid-late Carboniferous) burial diagenesis, which was overprinted by a post-Variscan, probably Permian and/or early Mesozoic, thermal pulse(s) in its central and western parts. The latter may have been related to advective heat transport and the circulation of hot fluids. In the siliciclastic rocks of the Culm Basin, the maximum palaeotemperatures varied from~200 ± 30°C in the E (in the Hradec-Kyjovice Formation) to~350 ± 30°C in the NW (in the Andìlská Hora Formation).