Andy SerkisAndy Serkis said that he based Gollum's voice on the sound of a cat coughing up a hairball.
The Lembas Bread that Sam and Frodo eat in the beginning of the film was actually shortbread cookies made by the art department
Gollum's pupils signal his frame of mind. "Treacherous Gollum" has narrow pupils; "friendly Gollum" has slightly wider pupils. This is most obvious in the scene when the two sides of his personality struggle with each other.
The role of Eowyn, the White Lady of Rohan, was first offered to Irish actress Alison DoodyAlison Doody in December 1999, who had to decline the part because she had just given birth to her second daughter. Miranda OttoMiranda Otto then auditioned for the same role.
The first sequel to be nominated for an Academy Award for Best Picture when the original film did not win the award itself, and the third sequel to be nominated for Best Picture.
The design for Gollum took over 100 maquette sculptures and over 1000 drawings to get right.
The Battle of Helms Deep features hundreds of spears made of cardboard tubes so that none of the charging horses would be injured.
Elijah WoodElijah Wood's sister is one of the refugees in Helms Deep, as is [?] Henry Mortensen, Viggo MortensenViggo Mortensen's son. Philippa BoyensPhilippa Boyens' son [?] Callum Boyens is the boy who gives Aragorn his sword, but that isn't his voice in the final cut. Callum's voice had changed by the time it came to do the looping, so a different voice was cast.
The Gollum that is briefly glimpsed in The Lord of the Rings: The Fellowship of the Ring is an entirely different creation than the one that appears in this film. It was during the filming of the second movie that Peter JacksonPeter Jackson realized that Andy SerkisAndy Serkis' physical performance would have to be employed in the digital creation of Gollum. So Weta Digital had to alter the design of one of the lead characters in the film, scanning Serkis' face so that they would be able to incorporate some of his facial characteristics (the fact that Jackson had also filmed a flashback to be included in The Return of the King with Serkis playing the original Smeagal only cemented this decision). This ultimately meant, however, that Weta Digital had only 2-1/2 months to redo two years' work. Serkis himself thought that the final result looked like a combination of his father and his newborn baby.