A lane departure prevention system comprises a traveling status detecting unit for detecting current lateral displacement and current yaw angle of a vehicle relative to a lane of travel, a departure detecting unit for detecting whether the vehicle is tending to depart from the lane of travel on the basis of current lateral displacement of the vehicle relative to the lane of travel as detected by the traveling status detecting unit; and a departure avoidance control unit for controlling the vehicle to avoid lane departure when the departure detecting unit detects that the vehicle is tending to depart from the lane of travel. The departure avoidance control unit calculating the extent of control necessary to avoid lane departure on the basis of current yaw angle of the vehicle detected by the traveling status detecting unit. Provision is made for preventing lane departure on a curving as well as a straight road.