Vehicle and method of controlling the same

A vehicle includes an authentication key system for identifying an authentication key, an occupant sensor for detecting an occupant and generating occupant information, a display to display information regarding vehicle operation, and a controller to control the authentication key system, the occupant sensor, and the display, wherein the controller is further configured to identify a starting authentication key used to turn on the vehicle, identify a driver's getting off in a state in which the vehicle is turned on, identify whether an assistant driver is present inside the vehicle based on the occupant information, and control the display to provide a notification that the starting authentication key has been removed from the vehicle or a notification of vehicle theft warning based on whether the starting authentication key or another authentication key is present and whether the assistant driver is present in the vehicle, after the driver gets off the vehicle.