Most famous moment of the series, lake scene, was not part of Austen's novel. Andrew Davies wrote the scene not because he wanted a sexual connection between Elizabeth and Darcy but to create "an amusing moment in which Darcy tries to maintain his dignity while improperly dressed and sopping wet".
In an interview fifteen years after the making of this series, screenwriter Andrew Davies said that at the moment that Darcy sees Elizabeth muddy and flushed from walking to Netherfield to see Jane, Davies wrote in the screenplay the stage direction that "this is the moment when Darcy suddenly realizes that he fancies Elizabeth very much and to his surprise he finds that he's got an erection." He said that he wrote this to make people laugh but also "for Colin to choose this as the moment when he's just got to act, being tremendously turned on."
Sue Birtwistle particularly wanted Colin Firth, a relatively unknown British actor in his mid-30s at the time, to play the wealthy and aloof Mr. Darcy. Birtwistle had worked with him on the mid-1980s comedy film Dutch Girls, but he repeatedly turned down her offer as he neither felt attracted to Austen's feminine perspective nor believed himself to be right for the role. Birtwistle's persistent coaxing and his deeper looks into the Darcy character finally convinced him to accept the role.
Casting the role of Darcy's young sister, Georgiana, proved hard as the producers were looking for a young actress who appeared innocent, proud and yet shy, had class and could also play the piano. After auditioning over 70 actresses, Simon Langton suggested Emilia Fox, the real-life daughter of Joanna David (Mrs Gardiner), for the part.
Helen Fielding, author of "Bridget Jones's Diary" had both the character of Mr. Darcy from this production and the actor Colin Firth in mind when she created the character Mark Darcy in "Bridget Jones." Firth played Mark Darcy in the "Bridget Jones's Diary" movie.
Hundreds of actresses between 15 and 28 auditioned for the role of Elizabeth Bennet and those with the right presence were screen-tested, performing several prepared scenes in period costumes and makeup in a television studio. Straight offers were made to several established actors.
The green striped gown with velvet Spencer jacket Anna Chancellor (Caroline Bingley) wears at Netherfield Hall is the same costume worn by Julia Davis (Elizabeth Elliot) at Kellynch Hall in Persuasion (2007), Vicki Pepperdine (Ann Dobbin) in the park scenes in Vanity Fair (1998), and an extra at the London party where Annabella Milbanke meets Byron in Byron (2003). The Spencer also appears, without the striped gown, in Little Dorrit (2008), worn by Emma Pierson as Fanny Dorrit.
The green pelisse with ribbon trim down the middle of the front and back Anna Chancellor (Caroline Bingley) wears when she visits Jane Bennet on Gracechurch Street is the same costume worn by a guest at the London Salon in Byron (2003), and by Alex Kingston (Mrs. Bennet) in the coach en route to the Netherfield Ball in Lost in Austen (2008).
The black Spencer with flowers embroidered on the collar and sleeves worn by an extra at the wedding is the same costume worn by Jackie Smith-Wood (Mary Crawford) to walk with Fanny in Mansfield Park (1983), by Natasha Little (Augusta Leigh) to visit Byron at his London apartment in Byron (2003), and by an extra in the London street when the Dashwoods arrive in London in Sense & Sensibility (2008).