The Premier League side signed the 26-year-old two weeks ago but he had not played 75 per cent of his country's fixtures in the last couple of years meaning he was unable to obtain a governing body endorsement.
Milijas had been a regular in the Serbia side since making his debut in 2008 and Wolves therefore decided to question the decision as the former Red Star Belgrade player only narrowly missed out on a permit.
The appeal, to a panel convened by the Football Association, has proved successful and Milijas is now able to join his new Wolves team-mates on their pre-season tour of Australia.
Milijas told the club's official website: "It is great news. I am really glad that I am now a Wolves player and can't wait to get started."
Wolves CEO Jez Moxey, who attended the hearing with manager Mick McCarthy, said: "We are delighted that we have successfully received a work permit for Nenad.
"With the case that we were presenting, we were always quietly confident that we would receive the permit but until it was completed we weren't getting carried away.
"We had a very good hearing and are delighted that Nenad will now be able to join the team in Australia and look forward to his Wolves career."