A 24-year-old service station attendant was left shaken after he was threatened with a knife during a hold-up at a Towradgi service station on Sunday night.
The knife-wielding thief entered Freedom Fuel in Towradgi Road about 11.50pm, and demanded cash and cigarettes.
Inspector Dan Richardson from Wollongong police said the victim handed over the items and was unharmed.
The thief took off into the night with another man, who is believed to have been waiting outside the store.
Both men were last seen running south along Carters Lane.
Freedom Fuel Towradgi manager Cass Laughton said the store employee was "a bit shook up but OK".
She said the employee had described the assailant as "young and really nervous".
"When the worker was closing [the robber] came in," Ms Laughton said.
"When he got to the counter, he pulled out a knife and demanded smokes, he was only in the store a minute."
Ms Laughton said counselling had since been offered to the employee, and CCTV footage of the incident was being reviewed and she would be reviewing the store's security systems.
The thief managed to take "a couple hundred dollars", Ms Laughton said.
The man was described as Caucasian with a slight accent, 165-170 centimetres tall, and of medium build.
He was wearing a black hooded jumper, dark pants with two white stripes and a black and white mask, and was carrying a pink and grey backpack.