Traction inverters are of critical importance in the propulsion systems of hybrid electric vehicles (HEVs). This paper focuses on major design aspects of HEV traction inverters comparing different types of the existing inverter topologies, reviewing the power specifications in commercialized hybrid electric vehicles, and discussing the advanced power module packaging technology. In addition, related applications of the wide bandgap power devices are reviewed. This paper also gives the overall overview of the current traction inverters and future trends for automotive applications.