Three men are alleged to have assaulted and threatened a service-station attendant in Rooty Hill before escaping with cash last night.
Police said the offenders entered the service station about 11.45pm on Tuesday and attacked an employee.
After taking money from the register, the three men escaped along Evans Street, police said.
Police are now looking for three suspects, all described as Aboriginal or Torres Strait Islander in appearance.
At the time the men were wearing dark-coloured, hooded jumpers.
Any information about the crime to Crime Stoppers, 1800333000.