Thermal conductivity measurements of 6H SiC crystals were done in the 300–500 K range by means of radiation thermometry. Both p‐ and n‐type crystals with carrier concentrations in the 8×1015 to 1020 cm-3 range were used. For the purest samples it was found that the thermal conductivity normal to the c axis is proportional to T-1.49, the room‐temperature value being 3.87 W/cm deg. It was also found that the thermal conductivity parallel to the c axis is about 30% lower than that normal to the c axis. Electrical data in the 100–1000 K range are also presented.