Bernard HillBernard Hill cracked his sternum while riding his horse.
Andy SerkisAndy Serkis said he based Gollum's desperation and cravings on the withdrawals of heroin addicts.
When Grima Wormtongue sees Saruman's army of 10,000, he is so shocked that a tear falls from one of his eyes. This wasn't in the script; it's something that Brad DourifBrad Dourif can do at will, and he and the filmmakers decided that it would work well for the scene.
Between takes, Brad DourifBrad Dourif stayed in character by continuing to speak with an English accent until all his footage had been completed. This was so convincing that, at the end, when he spoke with his normal voice again, Bernard HillBernard Hill thought that his English accent was real and that his American accent must be fake.
Brad DourifBrad Dourif had to shave his eyebrows off, and because he was recalled several times during the trilogy's filming, he ended up doing that five times over the course of three years.
Bernard HillBernard Hill was originally considered for the role of Gandalf.
Cameo: [Alan LeeAlan Lee] The Concept Designer can be seen as the Rohan collecting weapons at Helm's Deep (to the left when Aragorn yell's "Then I shall die as one of them!").
[?] Patrick McGoohan turned down the role of Gandalf due to poor health.
Orlando BloomOrlando Bloom originally auditioned for the role of Faramir.