A vehicle intrusion monitoring system that eliminates unnecessary image capture and transmission by controlling the timing of image capture by a camera installed inside a vehicle. A control ECU in the vehicle intrusion monitoring system issues a first image capture command to a camera triggered by an abnormality detected by a sensor while the system is in watch state. Then, the control ECU issues a second and further image capture commands only when an intrusion detector picks up an intruder inside the vehicle to eliminate unnecessary image capture and transmission.