The Lexus RX 400h is a crossover sports-utility vehicle that is also a hybrid. The first generation Lexus RX 400h made its debut in 2004 at the North American International Auto Show. Its Japan debut was in March 2005, and then appeared on US roads in the middle of 2005. It was powered by a mix of two engines - a 3.3 Liter 211 horsepower V6 engine and two electric motors. The first electric motor powered the front tires while the other powered the rear tires. The two motors have a horsepower rating of 68. The uniqueness of the system is that in normal driving conditions, only the front motor and the gas engine are used. The power from the other motor will be only used when the vehicle is traveling at full speed or the tires in front lose traction. If the Lexus 400h slows down or stops, the electric motors take over the running of the vehicle.

The Lexus RX 400h is equipped with a system to control traction and prevent the vehicle from skidding, anti-lock disc brakes on all four tires, 18 inch tires, back seat that is split in the ratio of 40/20/40 and can be slid and reclined. It also has headlights made of Xenon that are linked to the steering wheel, leather seats, a telescopic steering wheel, navigation system that has voice control, camera that is located at the back of the vehicle and heated front seats. In 2006, the Hybrid name was printed on the back side doors and a display screen was added to the navigation system that showed the readings from the gas engine and electric motors.