Police said a man held up workers at a Sonic in West Nashville.
The robbery happened just after 11:30 p.m. on Saturday at the restaurant on Charlotte Pike.
Workers told police a man armed with a gun walked through the front door and pointed the gun at one of them.
They said he demanded money from the safe.
When a worker told him she did not know the code he robbed them, took money from the cash register and left through the back door.
Police said the man was wearing a blue bandana, grey hoody and dark pants.