A driving assistance system (100) includes: an inter-vehicle distance detecting unit (32); a relative velocity detecting unit (33); an inter-vehicle distance control unit (40) to perform a first notification operation when the inter-vehicle distance becomes equal to or larger than a first distance and the relative velocity becomes equal to or higher than a first velocity, or equal to or larger than a second distance; and a forward vehicle start notifying unit (50) to set an inter-vehicle distance when the forward vehicle and the subject vehicle are stopped as a reference inter-vehicle distance, and to perform a second notification operation when a difference between the reference inter-vehicle distance and the inter-vehicle distance becomes equal to or larger than a third distance. The forward vehicle start notifying unit (50) does not perform the second notification operation at least until after the first notification operation is performed.