Industrialist John Hammond has created a theme park of cloned dinosaurs, Jurassic Park, on Isla Nublar, a fictional island off the Costa Rican coast. After a dinosaur handler is killed by a Velociraptor, the park's investors, represented by lawyer Donald Gennaro, demand that experts visit the park and certify its safety. Gennaro invites mathematician and chaos-theorist Ian Malcolm, while Hammond invites paleontologist Dr. Alan Grant and paleobotanist Dr. Ellie Sattler. Upon arrival, the group is shocked to see a live Brachiosaurus.
At the park's visitor center, the group learns that the cloning was accomplished by extracting dinosaur DNA from prehistoric mosquitoes preserved in amber. DNA from frogs was used to fill in gaps in the genome of the dinosaurs, and to prevent breeding, all the dinosaurs were made female by direct chromosome manipulation. The group witnesses the hatching of a baby Velociraptor and visits the raptor enclosure. During lunch, the group debates the ethics of cloning and the creation of the park; Malcolm warns about the implications of genetic engineering and scoffs at the park's conceptualization, saying that it will inevitably break down.
The group is joined by Hammond's grandchildren, Lex and Tim Murphy, for a tour of the park, while Hammond oversees the tour from the control room. The tour does not go as planned, with most of the dinosaurs failing to appear and the group encountering a sick Triceratops; it is cut short as a tropical storm approaches Isla Nublar. Most of the park employees leave for the mainland on a boat while the visitors return to their electric tour vehicles, except Sattler, who stays behind with the park's veterinarian to study the Triceratops.
Jurassic Park's disgruntled lead computer programmer, Dennis Nedry, has been bribed by Dodgson, a man working for Hammond's corporate rival, to steal fertilized dinosaur embryos. Nedry deactivates the park's security system to gain access to the embryo storage room and stores the embryos inside a container disguised as a shaving cream can. Nedry's sabotage also cuts power to the tour vehicles, stranding them just as they near the park's Tyrannosaurus rex paddock. Most of the park's electric fences are deactivated as well, allowing the Tyrannosaurus to escape and attack the group. After the Tyrannosaurus overturns a tour vehicle, it injures Malcolm and devours Gennaro, while Grant, Lex and Tim escape. On his way to deliver the embryos to the island's docks, Nedry becomes lost in the rain, crashes his Jeep Wrangler, and is killed by a Dilophosaurus.
Sattler helps the game warden, Robert Muldoon, search for survivors; they only find an injured Malcolm, just before the Tyrannosaurus returns. Grant, Tim, and Lex take shelter in a treetop, and encounter a Brachiosaurus. They later discover the broken shells of dinosaur eggs, and Grant concludes that the dinosaurs have been breeding, which occurred because of their frog DNA—some West African frogs can change their sex in a single-sex environment, allowing the dinosaurs to do so as well.
Unable to decipher Nedry's code to reactivate the security system, Hammond and chief engineer Ray Arnold reboot the park's system. The group shuts down the park's grid and retreats to an emergency bunker, while Arnold heads to a maintenance shed to complete the rebooting process. When Arnold fails to return, Sattler and Muldoon head to the shed. They discover the shutdown has deactivated the remaining fences and released the Velociraptors. Muldoon distracts the raptors, while Sattler goes to turn the power back on, before being attacked by a raptor and discovering Arnold's severed arm. Meanwhile, Muldoon is caught off-guard and killed by the other two raptors.
Grant, Tim and Lex reach the visitor center. Grant heads out to look for Sattler, leaving Tim and Lex inside. Tim and Lex are pursued by the raptors in a kitchen, but they escape and join Grant and Sattler, who have returned. The group reaches the control room and Lex uses a computer to restore the park's power, allowing them to call Hammond, who calls for help. As they try to escape by the front entrance, they are cornered by the raptors, but they escape when the Tyrannosaurus appears and kills the raptors. Hammond arrives in a jeep with Malcolm, and the group boards a helicopter to leave the island.
Sam Neill as Dr. Alan Grant
Laura Dern as Dr. Ellie Sattler
Jeff Goldblum as Dr. Ian Malcolm
Richard Attenborough as John Hammond
Bob Peck as Robert Muldoon
Joseph Mazzello as Tim Murphy
Ariana Richards as Lex Murphy
Samuel L. Jackson as Ray Arnold
Wayne Knight as Dennis Nedry
Martin Ferrero as Donald Gennaro
B.D. Wong as Dr. Henry Wu
Jerry Molen as Dr. Harding
Miguel Sandoval as Juanito Rostagno
Cameron Thor as Dodgson
Greg Burson as the voice of Mr. DNA
Richard Kiley has a cameo appearance as the voice of the Jurassic Park tour vehicle guide
the first installment in the Jurassic Park franchise, and the first film in the Jurassic Park trilogy, and is based on the 1990 novel of the same name by Michael Crichton and a screenplay written by Crichton and David Koepp.