A territorial surveillance and/or security control system based on monitoring vehicle license plates, and having a number of mobile surveillance units (2) for reading vehicle license plates and generating alarms during patrol by the mobile surveillance units (2), and a permanent surveillance centre (3) communicating with the mobile surveillance units (2) to locate the mobile surveillance units by radio, to gather, file, and consult the license plates detected by the mobile surveillance units (2), to handle the alarms generated by the mobile surveillance units, and to update a list of wanted license plates. Each mobile surveillance unit (2) includes a vehicle (4) equipped with an on-vehicle navigation system (5); and a license plate reading device (6) on the vehicle (4) and communicating with the on-vehicle navigation system (5) of the vehicle (4), which controls communication with the permanent surveillance centre (3) to update the list of wanted license plates, and to transmit any alarms generated by the mobile surveillance unit (2).