The robbery happened just before 5 p.m. at the Dollar General located in the 7900-block of Fayetteville Road.
Police said a black male demanded money from a cashier at knifepoint and left the store on foot with an undetermined amount of cash.
Police said the man is between 6 feet and 6 feet 2 inches tall and weighs between 180 to 200 pounds.
He was described as having a medium complexion with a full, black beard and a gray goatee. He was wearing a gray, knit cap, a blue jacket, carpenter-style, blue jeans, and white tennis shoes.
No injuries were reported.
The Garner Police Department is asking the public to call (919) 772-8810 with any information that could lead to the arrest of the subject.