The book of The Two Towers begins with the chapter, 'The Departure of Boromir', where he's found dead. The filmmakers decided to end the cinematic version of The Fellowship of the Ring with Boromir's death to provide a full arc for the character within the single film, whereas the book ends with his fate unresolved.

On the 2 disc DVD, theatrical version of the movie, when the fellowship is leaving Lórien in the boats, the entire time Frodo is sitting at the front of the boat with Sam behind him, and Aragorn behind Sam. But when they pass the Argonath, Aragorn taps Frodo on the shoulder. He is sitting right in front of him and Sam is in the front of the boat. However, this is corrected in the extended version because there is a scene right before they see the Argonath where they get out of the boats. They spend the night on shore, so it is actually a different day from when they left Lórien to when they see the Argonath. So it is assumed that Sam and Frodo just switched places the next day.

When the trailer was released on the Internet on April 7, 2001, it was downloaded 1.6 million times in the first 24 hours.

Two of the children Bilbo is telling his troll story to are Peter Jackson and Fran Walsh's children.

In the scene where Merry and Pippin light the firework, Billy Boyd was so shocked by the firework going off when it was being filmed that he actually let out the high pitched shriek that is heard when the tent goes up. In some of the behind the scenes stuff, Dominic Monaghan makes fun of Billy by calling him 'a slightly feminine character', while poor Billy tries to defend himself.

When the Fellowship is taking the path of Caradhras, there is a shot of Saruman shouting on the top of Orthanc, and the camera swoops around closer to him. If you slow it down or pause it you can see a huge white bandage on one of the fingers of his left hand. Christopher Lee (Saruman) had hurt his finger shutting it in a door. This is confirmed by the DVD audio commentary.

In the prologue there is a shot of Bilbo picking up the ring. For this, Ian Holm had to have his face taped back to make him look younger.

When the Fellowship start poking their heads out of the snow after they've been buried on the mountain, Orlando Bloom (Legolas) is coming out of real snow (the rest are on a set).

When they are on the ledge of the snowy mountain, notice that Legolas is walking on top of the snow while the others are trudging through it.