Our study shows that rhombohedral boron carbide with a composition B4C (ToF-ERDA) can grow epitaxially on 4H-SiC(0001 ̅ ) at 1300 °C by CVD using triethylboron as single source precursor in H2. The epitaxial relationships were r-B4C( 0001 )[ 101 ̅ 0 ]∥ 4H-SiC( 0001 )[ 101 ̅ 0 ] as seen from pole figure measurements. XRD and SEM revealed that higher deposition temperature results in co-deposition of graphite, and lower deposition temperature results in polycrystalline boron carbide. Deposition on 4H-SiC(0001) resulted in polycrystalline r-BxC with preferred orientation and amount of co-deposited graphite varying with the deposition temperature and the gas residence time in the CVD reactor. We suggest that these results are explained by the ability of the SiC surface to supply carbon for the initial growth of r-BxC. These results give further insight on the influence of growth conditions for this material system and enable the use of epitaxial boron carbide thin films for their intended applications in electronic and thermoelectric devices.