The crime was reported around 12:30 a.m. after a resident discovered the two victims in their car with their hands tied behind their backs in the 700 block of Castro Street, police said.
The victims, ages 27 and 25, told police that they had just pulled into a parking lot at 2600 San Leandro Blvd. and gotten out of their car when a man with a gun approached them and forced them back into the vehicle.
The suspect, described as a black man about 6 feet 3 inches tall and 180 pounds who was wearing dark clothing, ordered the victims drive to an ATM in the 1200 block of Marina Boulevard, police said.
He forced one of the victims to withdraw about $500 from the machine, and then had the victims drive to the 700 block of Castro Street, where he tied them up and fled with the cash, police said.
The two victims honked the car's horn until the resident found them.
Police are asking anyone with information about the crime to contact San Leandro police at (510) 577-3248 or through the department's website at www.sanleandro.org.