This paper describes a newly developed thermoelectric infrared imaging sensor, having a 48 x 32 element thermoelectric focal plane array (FPA), and two experimental vehicle systems. One is a blind spot pedestrian warning system that employs four infrared imaging sensors. This system helps alert the driver to the presence of a pedestrian in a blind spot by detecting the infrared radiation emitted from the person’s body. The systemcan also prevent the vehicle from moving in the direction of the pedestrian. The other is a rearview camera system with an infrared detection function. This system consists of a visible camera and infrared sensors, and it helps alert the driver to the presence of a pedestrian in a rear blind spot. The FPA is basically fabricated with a conventional IC process and has the potential for low cost.