The gear transmission of an electric vehicle (EV) is very different from that of a conventional gasoline/diesel vehicle due to the different torque/speed characteristics of the electric motor and internal combustion engine. Typically, it has a one-speed, two-stage helical gearbox arrangement. Despite its simplicity, the EV gearbox requires high load-carrying capacity within the compact, lightweight package, high efficiency, high NVH performance, lengthy lifetime, and low cost in mass production. The EV gearbox operation is primarily unidirectional, with power recuperating during a vehicle deceleration. Therefore, utilizing the asymmetric gear tooth shape is beneficial to optimize the EV gearbox’s characteristics. The design objective of asymmetric tooth gears is to maximize the performance of the drive tooth flanks at the expense of the performance of opposite coast tooth flanks. The coast tooth flanks are mostly unloaded or lightly loaded during a relatively short operation time. Applying the Direct Gear Design® method provides comprehensive asymmetric tooth shape optimization, including the drive and coast tooth flank profiles and the tooth root. Such asymmetric tooth profiles considerably amplify power transmission density, increase load capacity and transmission efficiency, and reduce size and weight beyond those limits achievable with conventional gears with symmetric teeth. The paper also presents design and performance data of asymmetric tooth gears compared to originally designed symmetric tooth gears for the EV gearbox.