The incident happened at around 12.10am today in Station Road near the Post Office.
The man was walking on the pavement when a car pulled up behind him and he heard people getting out.
He was then pushed from behind causing him to fall, before being pinned down and punched in the face.
A second man searched his pockets stealing his wallet and mobile phone before the offenders drove off.
The victim suffered cuts and swelling to his face.
Detective Constable Paul Rogers said: “This was an unprovoked attack and I am appealing for any information which might help the police investigation.
“In particular, I am asking anyone who witnessed the incident or knows the identities of the offenders, to call Oswestry police station on the 101 number.”
Information can also be given to the anonymous Crimestoppers independent charity by calling 0800 555 111.
Shropshire Live is regulated by