The robber, who's roughly 30-years old, walked into a US Bank on NW 61st Street and 15th Avenue NW just before 3 p.m. and told everyone to get on the ground.
The man implied he was armed, demanded money from a teller and then left the bank with an unknown amount of cash.
Police say he drove away in a black, two-door Porsche 944 Turbo hatchback.
The robber stands 5'8" to 5'10" tall, has a medium build and was wearing a black jacket, jeans, a mask and sunglasses. Police say he is either white or Asian.
Robbery detectives are now handling the investigation. Anyone with information is asked to call the FBI - Seattle Safe Streets Task Force at (206) 622-0460.