In a warning device for a vehicle, a basic target current value setting unit sets a basic target current value based on a steering torque and a vehicle speed. When a lane deviation determining unit determines that there is a high possibility that a vehicle will deviate from a lane, a warning vibration wave generator generates a warning vibration wave containing a plurality of frequency components. A target current value is computed by adding the warning vibration wave to the basic target current value. A motor current to be applied to an electric motor is controlled so as to approach the target current value.