A Tesco delivery driver was punched in the head by a gang of five men.
Police are seeking witnesses to a robbery in Western Road, Hailsham at about 4.50pm on Monday.
The 23-year-old had just pulled over for a phone call when the gang targeted him.
After two punched him, two entered his cab, stole his keys and tried to steal other items too.
They then scattered and made off in different directions without taking anything else.
He was treated for bruising and cuts to his head and body.
Witnesses should call Sussex Police on 101.