Around 9:56 p.m., one of the suspects entered the parlor in the 300 block of Vallejo Street posing as a customer. He then took out a firearm and was joined by the second suspect, who was also armed, police said.
The suspects detained four employees and took their valuables, including watches and jewelry. The pair then ransacked two rooms, appearing to be looking for more valuables.
The suspects then fled from the business and are believed to have left in a car, police said.
No one was injured in the robbery.
The value of the items taken has not been determined, police said. Anyone with information about the robbery is encouraged to call Petaluma police Officer Art Farinha at (707) 778-4372.