A 20-centimetre kitchen knife was used in an attempted hold-up at a Woonona service station on Monday.
Wollongong police inspector Brian Wyver said the BP employee, 22, ran from the store after a man pulled the knife at 8pm before the offender also fled without taking anything.
The man is described as between 40 and 50-years-old, with fair skin and a bald head.
He was wearing black sunglasses, a blue hoodie with a thick grey zip-up jacket over the top, black track pants with a white logo, white joggers and black gloves.
Anyone with information should contact Wollongong police or Crime Stoppers on 1800 333 000.