A dangerous driving warning device configured to warn a host-vehicle that the host-vehicle is agitated by an other-vehicle, the dangerous driving warning device comprising: a host-vehicle information acquisition unit (121A, 122A, 13A, 14A, 15A) configured to acquire host-vehicle information including at least one of travel information of the host-vehicle, biological information of a driver of the host-vehicle, and a facial expression of the driver of the host-vehicle; a communication unit configured to acquire an agitating degree indicating a degree to which the other-vehicle is agitating the host-vehicle, by means of radio communication, the agitating degree being calculated based on at least one of travel information of the other-vehicle, biological information of a driver of the other-vehicle, and a facial expression of the driver of the other-vehicle; an agitated degree calculation unit configured to calculate an agitated degree indicating a degree to which the host-vehicle is agitated by the other-vehicle, based on at least one of the travel information of the host-vehicle, the biological information of the driver of the host-vehicle, and the facial expression of the driver of the host-vehicle included in the host-vehicle information; a danger degree determination unit configured to determine a first evaluation value by referring to a first evaluation value table in which the agitated degree is classified into a plurality of stages with an evaluation value set for each of the plurality of stages, to determine a second evaluation value by referring to a second evaluation value table in which the agitating degree is classified into a plurality of stages with an evaluation value set for each of the plurality of stages, and to determine a warning content in accordance with the first evaluation value under a condition that the second evaluation value is equal to or above a predetermined evaluation value; and a presentation unit configured to present the warning content. a host-vehicle information acquisition unit (121A, 122A, 13A, 14A, 15A) configured to acquire host-vehicle information including at least one of travel information of the host-vehicle, biological information of a driver of the host-vehicle, and a facial expression of the driver of the host-vehicle; a communication unit configured to acquire an agitating degree indicating a degree to which the other-vehicle is agitating the host-vehicle, by means of radio communication, the agitating degree being calculated based on at least one of travel information of the other-vehicle, biological information of a driver of the other-vehicle, and a facial expression of the driver of the other-vehicle; an agitated degree calculation unit configured to calculate an agitated degree indicating a degree to which the host-vehicle is agitated by the other-vehicle, based on at least one of the travel information of the host-vehicle, the biological information of the driver of the host-vehicle, and the facial expression of the driver of the host-vehicle included in the host-vehicle information; a danger degree determination unit configured to determine a first evaluation value by referring to a first evaluation value table in which the agitated degree is classified into a plurality of stages with an evaluation value set for each of the plurality of stages, to determine a second evaluation value by referring to a second evaluation value table in which the agitating degree is classified into a plurality of stages with an evaluation value set for each of the plurality of stages, and to determine a warning content in accordance with the first evaluation value under a condition that the second evaluation value is equal to or above a predetermined evaluation value; and a presentation unit configured to present the warning content.