The woman, who is only about 5 feet tall, robbed the U.S. Bank on Ralston Avenue at about 10:50 a.m. on June 10, Belmont police said.
She entered the bank in sunglasses, an oversized T-shirt and a white New York Yankees hat and approached the teller, demanding money, according to police.
The woman, who also carried a distinctive shoulder bag, took an undisclosed amount of cash and fled, police said. No weapons were seen.
She was last seen in the parking lot of a nearby Walgreens.
Anyone with information about the robbery is asked to call the Belmont Police Department at (650) 595-7400.
