It happened just after 11:15 a.m. Dec. 3 at the First Citizens Bank in the 200 block of Fayetteville Street.
Police said the suspect approached a teller, passed a note demanding money, and fled the bank after the teller complied.
Police are looking for an African-American man of average build who was wearing a white shirt under a dark-colored jacket, blue pants and a brown hat. The suspect also reportedly had some type of facial hair, like a mustache, beard or goatee.
He was last seen traveling on foot north on Fayetteville Street towards the North Carolina State Capitol.
Anyone with information on the bank robbery is asked to call Raleigh CrimeStoppers at (919) 834-HELP.