A device (10) for determining a state of attentiveness of a driver of a vehicle (1) is disclosed. The device includes an image capture unit (11) onboard said vehicle (1), said image capture unit (11) being suitable for capturing at least one image of a detection area (D) located in said vehicle (1), and an image processing unit (15) suitable for receiving said captured image and programmed to determine the state of attentiveness of the driver (4), according to the detection of the presence of a distracting object in one of the hands of the driver (4), which hand being located in the detection area (D).