Police say the man got out of his car with a gun and demanded a student's book bag as she walked along Campus Drive and Maxwell Street.
The suspect is described as a bald black male between 27 and 30 years old with medium to dark complexion, big cheeks, round eyes and a stocky build. He is 6'1" to 6'2" tall and was wearing a black sweat shirt and dark pants.
University police have stepped up patrols in the Campus Drive area where the crime took place.
Anyone with information about the incident is asked to call Duke Police at (919) 684-2444 or CrimeStoppers at (919) 683-1200.