The Lost World: Jurassic Park deviates significantly from Michael Crichton's book, with Spielberg's own additions. Spielberg's film introduces new characters like Peter Ludlow not in the original book, shifting the narrative. Key changes like Eddie's death, the T-Rex in San Diego, and Sarah's role make the movie a Hollywood twist on the novel.

There are many differences between The Lost World: Jurassic Park and the book that it is based on, The Lost World. Written by Jurassic Park author Michael Crichton, The Lost World provided a sequel to 1990's Jurassic Park on its publication in 1995. After the critical and commercial success of Steven Spielberg's adaptation of Crichton's first novel, Spielberg's team went after a sequel. It was this push that resulted in Crichton's sequel, which formed the basis of the movie, alongside Spielberg's own imaginings. To this day, The Lost World: Jurassic Park is one of the best Jurassic Park movies.