The robbery at the bank at 401 Sir Francis Drake Blvd. in the Bon Air Center happened around 5:30 p.m., Sgt. Julie Gorwood said.
The suspect, dressed in black, gave a teller a demand note and placed a bag on the counter, Gorwood said.
He fled with the cash through the east door of the bank in an unknown direction, Gorwood said. Neither a weapon nor a vehicle was seen.
The suspect is a white man in his 40s who is between 5 feet 7 inches to six feet tall with blue eyes and had a dirty blond Fu Manchu mustache, Gorwood said.
He was wearing a black cap, black jacket, black gloves, black pants and shoes, Gorwood said.
Anyone with information is asked to call Twin Cities police at (415) 927-5150.