A man assaulted a 35-year-old sales assistant at a Goulburn bottle shop before fleeing the store with cash stolen from the cash register, police say. 

Police say the man entered the Brewer Street store shortly before 7pm on Saturday and threatened the sales assistant before eventually assaulting him. He received minor injuries from the attack.

Police from the Goulburn Local Area Command were called to the store and conducted an extensive search for the man.

A crime scene was established and several items were seized by police for forensic examination.

The man, who has not been found, covered his face with a T-shirt during the robbery.

Police are urging anyone with information about the incident to contact authorities.