Neither the contents of the note nor the amount taken is being released by police.
"Responding patrol units quickly arrived and established a perimeter, however, the suspect fled prior to their arrival," a Pleasanton police news release said. "Further investigation revealed that the suspect entered the bank and handed a teller a threatening note."
The man is described as a black male, 30 to 40 years old, 5 feet 8 inches to 5 feet 9 inches tall, clean shaven, with a medium build. He was wearing a white hooded sweatshirt with a dark stripe down the back, gray pants and sunglasses. The suspect fled in what police describe as a vehicle similar to a 1970s era Ford Ranchero, brown in color with a white camper shell.
No weapon was seen and no one was injured in the robbery, and neighboring police departments have been informed about the holdup. Anyone with information is asked to contact the Pleasanton Police Department at 931-5100.