The actor's role in the sequels were in doubt as Marvel were reportedly unwilling to agree to his pay demands.
But Robert and the studio have come to an agreement which will see him reprise the role of Tony Stark/Iron Man in 'Marvel's The Avengers 2' and 'Marvel's The Avengers 3', reported Ace Showbiz.
A statement on Marvel's website said, "I am Iron Man. Tony Stark's famous closing line to the very first 'Iron Man' film takes on new life today as Marvel is pleased to announce the signing of Robert Downey, Jr to reprise the role of the 'billionaire, genius, playboy, philanthropist'."
The sequel will start production on March 2014 and is being written and directed Joss Whedon.