Joe Wright was not initially keen on Keira Knightley playing Elizabeth, believing her to be too attractive. He changed his mind upon meeting her, deciding her tomboyish attitude would be perfect for the part
Keira Knightley was preparing for her role in Domino while she was filming this, and had already cut her hair. She had to wear a wig during the last few weeks of filming and long sleeves to hide her muscles.
The English Country Dances done in the film are: Young Widow, Wakefield Hunt, The Bishop, Dutch Dollars, Tythe Pig, Black Bess, Duke of Gloucester's March, and Moniek's Maggot (a modern composition done in the traditional style, danced in the film to a tune by Henry Purcell.)
The dinner table scene at Lady Catherine's was the first scene shot for the film. Elizabeth's conversation with Mr. Wickham under the tree was the last. Filming at that location, Burghley House in Linconshire, lasted from the 18th to the 22nd of July, 2004, according to the house's website. In the film (and the novel), the house is called Rosings. Filmed almost entirely on location. The only set built for the film was the Meryton Assembly room where Darcy and the Bingleys are first introduced, because assembly rooms of the type no longer survive in England, or are at least very hard to find nowadays. Building the set also allowed the crew to build it to their exact specifications. Filming on a real location that was that narrow would have been incredibly difficult anyway.
The actresses who make up the Bennett family (Keira Knightley, Rosamund Pike, Jena Malone, Talulah Riley, and Carey Mulligan went to the Bennett house location, in Kent, before the crew, and played Sardines (similar to Hide and Seek in America) in order to get better acquainted with the house and each other before filming began.
All the exterior Pemberley sequences and some of the interior, including the sculpture gallery, were shot at Chatsworth House, property of the Duke of Devonshire. As the house functions as a private home and is also the most visited stately home in England, several of the interior shots could not, however, be done there and were instead shot in Wilton House, Wiltshire.
At the beginning of the movie, Elizabeth is shown reading a novel titled "First Impressions" - this was Jane Austen's original title of her novel before she altered it to "Pride and Prejudice". Additionally the text of the visible pages is readable when paused; it is the last chapter of Pride and Prejudice, with names changed.
According to the director's commentary, Carey Mulligan (Kitty) thought of her mother's funeral during her first crying scene (also her first film). On subsequent takes, when she ran dry, Carey thought of what song would be played at her own funeral. It didn't work quite as well.
The militia uniforms seen in the parade sequence came from the "Sharpe" TV series. There was no unit in the British Infantry at the time with yellow facings on their collars and turn backs, however Bernard Cornwell, author of the Sharpe series created a regiment from whole cloth called the "South Essex" which he described as having yellow facings on their collars. The uniforms were created for the Sharpe's TV series, and were pulled from the wardrobe department for this film.
During Mr. Bingley's private ball, when Miss Bingley and Mr. Darcy are dancing with each other, Miss Bingley says, "I can't help feeling that someone is going to produce a piglet and make us chase it." The song they are dancing to is called "The Tythe Pig."
Mr. Darcy reveals to Lizzy that his sister is to have 30,000 pounds. This sum is her dowry, given to her upon her marriage from the family. It would amount to an income of 1,500 pounds a year on a 5 percent interest, making Miss Georgiana Darcy a very eligible young woman. In comparison, Mr. Bennet has agreed to give the married Lydia 100 pounds a year, meaning her dowry, as well as those of her four other sisters, is only 2,000 pounds.
Director Joe Wright managed to cast Judi Dench reportedly by writing her a letter saying 'I love it when you play a bitch', and petitioned Donald Sutherland to take the part of Mr Bennet. As Wright said in an interview in 2005, "We ended up having a long email correspondence about everything from 18th-century agriculture to my relationship with my father. I cast Donald a) because he's a god, and b) because you needed someone of that strength to handle those six women." On a similar note, he mentioned he was "reluctant" to cast Simon Woods as Mr Bingley, as he had previously been in a relationship with actress Rosamund Pike: "'I tried very hard not to cast Simon, but I knew he was perfect. Finally I rang Ros and asked if she'd mind, and she said, "Absolutely not". They hadn't seen each other for two years but the next day they were dancing together. It was lovely".
Emma Thompson did an uncredited and unpaid re-write of the script. She receives a "Special Thanks" credit at the end of the film. One of the two scenes that Emma Thompson wrote was the scene in which Charlotte Lucas tells Elizabeth Bennet that she will marry Mr. Collins. The other one is the scene in which Elizabeth Bennet tries to tell Mr. and Mrs. Gardiner and Darcy about Lydia's elopement with Wickham. Here Keira Knightley's walking in and out of the room was Emma Thompson's idea according to Joe Wright's DVD commentary.
The frequent close-ups of Matthew Macfadyen's hand are a reference to the fact that the ultimate goal of the Bennet sisters' lives is a wealthy man's "hand" in marriage, and a foreshadowing of the fact that Elizabeth does in fact eventually win Darcy's "hand".