A system and method for alerting drowsy driving are provided. The system includes a d controller configured to analyze a driving pattern of a vehicle to detect a dangerous driving pattern. In addition, the controller is configured to analyze a face image of a driver to detect an eye pattern maintained for a predetermined period of time or longer. Further, the controller is configured to determine that the driver is driving while drowsy when the eye closing for the predetermined period of time or longer and the dangerous driving pattern are simultaneously detected.