The man was delivering parcels on Alexandra Road, Swallownest, in Rotherham, when the two men tried to steal some of the items from him.The delivery driver bravely challenged the men but they repeatedly drove their moped at him, knocking him over and assaulting him.
The incident happened at around 2.45pm on April 1, and police are now asking for the public's help in catching the two robbers.
Detective Sergeant Leanne Hearnshaw, of South Yorkshire Police, said: “The driver challenged the men but was then assaulted by them and knocked over after the moped was driven at him repeatedly.
“This was a nasty assault on a man who was simply going about his daily job, this should not be happening on our streets and everyone who witnessed this was left very distressed.
“The men were described as white, in their early 20s, and they were wearing black clothing and balaclavas. They are believed to have been riding a black moped.
“Our enquiries are progressing, but we’re appealing for anyone who might know these men or has information about what happened to get in touch with us.”
Anyone with information is asked to contact police on 101, using incident number 552 of April 1.
South Yorkshire Police said there has been an increase in delivery drivers being victims across the county.
Drivers are being urged to remember that car thieves and opportunists are in the area and they will take their chance to steal parcels and their vehicle.