The director's record-breaking film will return to 3D theaters worldwide on Friday for a limited-run, as "Avatar: Special Edition."
And he's sprinkled an extra nine minutes of footage throughout the computer-generated blockbuster, including a new sex scene between Sam Worthington's character Jake Sully, and his Na'vi lover Neytiri, played by actress Zoe Saldana.
New shots of a schoolhouse run by Sigourney Weaver's character Dr. Grace Augustine and the death of Na'vi clansman Tsu'tey will also be featured.
But Cameron isn't finished adding extra features to keep fans hooked - he will add another seven minutes of footage to a special-edition DVD scheduled for release in November.
He tells the New York Post, "It's for those that don't mind a movie that's pushed to 257 minutes... it's strictly for hyperfans."
"Avatar" has earned $2.7 billion in box office revenue worldwide since its release last December, and has become the most successful film ever released.