We report experimental results of photon emission from silicon carbide MOS transistors. Emission spectra have been measured on 6H and 4H-SiC MOSFETs, in a region below the bandgap energy of the SIC material. The relationship found between light intensity and the substrate and drain currents shows that the origin of photon emission can be ascribed to recombination processes. In both cases we observed a decrease of the emitted light with increasing photon energy. Two distinct peaks are always observed, located around 1.5 and 2.5 eV, respectively.