A man has been treated for minor injuries after he was assaulted with a barbecue fork early on Thursday.

Police allege the 24-year-old was the victim of a robbery at a McDonald's restaurant in Ballarat Road, Footscray, about 4.30am.

Three men, one armed with the weapon, approached the man and stole an undisclosed amount of cash.

The victim, a Footscray resident, was treated at the scene.

An unidentified man is assisting police with their inquiries.

Anyone with information is asked to phone Crime Stoppers on 1800 333 000.