A method is for monitoring a taillight of a vehicle having a camera directed to the rear, wherein the taillight includes a light unit. The taillight and/or light surroundings illuminated by the taillight is/are captured by the at least one camera and camera signals are output. A camera image having pixels is provided depending on the output camera signals. The taillight of the vehicle or the light surroundings is represented in light pixels of the respective camera image. Brightness values are ascertained and evaluated at least for the light pixels of the camera image. A functional status of the taillight is ascertained depending on the ascertained brightness values and output.