Abstract: The present invention relates to a system for monitoring the state of vigilance of an operator including: a camera furnished with a sensor responsive in the near infrared, a circuit for real-time processing of the signals delivered by the camera, so as to determine characteristic points for each of the images. By analysing the characteristic points, the information relates to a part at least of the indicators including: the inclination of the head in three orthogonal directions, the position of the pupil, the opening of the eye, and/or the configuration of the mouth. Furthermore, a computer controlled by a program determines the state of vigilance as a function of the indicators and of their temporal evolution.