In the book, Bridget Jones is obsessed by Colin Firth from Pride and Prejudice (1995), and even gets to meet him for an interview. This plotline is omitted from this movie, where Firth played her love interest Mark Darcy. They did, however, film the interview scene with Colin dressed in his street clothes, and Renée Zellweger in character. The scene is included in the DVD extras.
(at around 1h 23 mins) On Episode dated 22 October 2004 (2004), Hugh Grant and Colin Firth revealed the scene of them fighting each other was not choreographed.
The role of Daniel Cleaver (Hugh Grant) only had a small appearance in the book. The character was so memorable and popular that his part was extended specifically for this movie.
During filming in Thailand, the cast stayed on Nai Yang Beach, close to the airport in Phuket. They often drank at the little shack bars down on the beach, especially "Mama Mia's". In 2004, all of those bars and restaurants were destroyed in the tsunami. The pianist at the J.W. Marriott in Phuket, Stuart Hopkins, who was also a regular at the bar made extensive attempts to contact the cast. In June 2005, a large package arrived for his attention. It was from Renée Zellweger containing many things such as t-shirts, caps, and a big movie poster signed by her and other cast members. Over the years, the bars on the beach were re-built, and the poster still hangs proudly in Mama Mia's bar as of August 2009.
Drug smuggling is a very serious offense in Thailand, even more serious than murder. The rationale is that a murder might result in one death where drugs kill hundreds.
Jeremy Paxman: (at around 19 mins) BBC newscaster and presenter of University Challenge greeting Daniel Cleaver in passing and compliments him on his show. The scene that was filmed in one continuous shot, which required numerous retakes and took a long time to do. He commented that he usually covered the entire world news in the time it took to film this short sequence for a movie.