It is believed an unknown man attended a store on Frankston – Dandenong Road about 7.10pm.
He threatened the attendant with a knife.
The man made demands for cash before fleeing the scene on foot.
No one was injured during the incident.
Police have released an image of a man they believe may be able to assist them with their enquiries.
At the time of the incident he was wearing a black jacket with a hood and brown pants. He was also wearing distinctive red running shoes.
Anyone with information about the armed robbery is urged to contact Crime Stoppers on 1800 333 000 or visit www.crimestoppersvic.com.au
