The hunk will present a 90 second preview from the final film in the series during the live awards show. He will be joined by Taylor Lautner and other cast members from the film to introduce the footage at the Staples Center in Los Angeles.
There is no word as to whether Robert's co-star and recent ex-girlfriend Kristen Stewart will also be at the awards.
Other presenters on the night will include boy band The Wanted, Andy Samberg, Ke$ha and Miley Cyrus.
The entire VMAs will be hosted by Kevin Hart, who has already joked he is planning to strap up Kanye West, so he cannot do another of his famous stage invasions.
He joked: "With Kanye we've got a seatbelt for his seat that he can't get out of, little things that they never thought of in the past to make sure it all goes OK this year.
"No, actually I hope someone does something stupid though, that's what it's all about.
We need stuff to talk about the next day. It's the MTV VMAs. This is where all the stupid stuff can happen and should happen."
The night also has an incredible line up of performers including Lil Wayne, 2 Chainz, Nicki Minaj, Rihanna, Taylor Swift, Green Day, Pink and One Direction.
Alicia Keys will also take to the stage, debuting a new song for the first time.
The MTV VMAs take place tomorrow and will be broadcast live on MTV in the US at 20:00 Pacific Time.