Abstract: Wide bandgap semiconductors, such as silicon carbide (SiC) and gallium nitride (GaN), are considered to be excellent candidates for high power, high frequency and high temperature applications in the commercial and military power distribution and conversion systems. The advantages of wide bandgap materials over the conventional Si and GaAs include wide bandgap, high saturation electron velocity, and high critical electric field. In this paper, the recent progress in the development of high-voltage SiC and GaN power switching devices is reviewed. The experimental performance of various rectifiers and transistors, which have been demonstrated, is discussed. Market and technical challenges on SiC and GaN power devices are also described. The future trends in device development and commercialization are pointed out.