The robbery was reported at about 10:25 p.m. in the 400 block of Pimlico Drive, according to police.
The suspects allegedly approached victims who were seated on the sidewalk and brandished a knife and demanded money, police said.
The suspects threatened the victims and punched one of them before fleeing to a four-door white 1990s Acura Legend with gold lettering, and driving northbound on Jones Road.
Arriving officers searched the surrounding neighborhoods for the suspects, who were not located. No injuries were reported during the robbery.
The suspects are both described as Hispanic or Pacific Islander men in their early twenties. The first suspect is about 6 feet 2 inches tall with black curly hair and weighs about 250 pounds. He was last seen wearing all dark clothing and was armed with a knife, police said.
The second suspect is about 6 feet 4 inches tall with long black hair in a ponytail and weighs about 250 pounds. He was last seen wearing a black wrist brace, a white T-shirt and black pants with red lettering on them, according to police.
The investigation into the robbery is ongoing, and anyone with information about the incident should call the Walnut Creek Police Department at (925) 943-5844.