A parking assistance apparatus obtains a target travelling route from a present position of a vehicle to a target parking position when it is determined that a predetermined route obtaining condition is satisfied. In addition, the parking assistance apparatus executes a travelling assistance processing for controlling at least a steering angle of the vehicle such that the vehicle travels along the target travelling route when a predetermined assist starting condition is satisfied. The target travelling route is obtained such that a distance between the vehicle and the object is kept larger than the threshold distance while the vehicle travels along that target travelling route The threshold distance is stored in the parking assistance apparatus and a configurable value which can be changed by a driver of the vehicle.