A stormy night, off the coast of Costa Rica, a young man is admitted into a hospital with a wound caused by a small, reptilian animal. He is diagnosed with severe nausea and some sort of blood poisoning. The man dies leaving the doctors with a problem of deciphering the origin of the disease and what it is. On the same island, approximately 20 miles north, a family is taking a vacation from their normal life in the city. Among these people, is a young girl with a knack for drawing and curiosity for animal life.
This young girl believes that her family will spot a sloth, which is the only mammal left on her list of animals to see. As she wanders off she stumbles upon a small lizard that shes never seen before and begins sketching the creature. The small animal seems to feel threatened so it attacks the girl in defense. The girl gets taken to a hospital for many of the same symptoms the young man was facing. Allen Grant, a paleontologist, with his girlfriend Elly Sadler, is on the verge of discovering the most intact fossil of his favorite dinosaur, the velociraptor.
When the two decide to start celebrating, they are visited by a very intelligent scientist, John Hammond. Hammond brings long a proposal that the two come with him to his special new park for an evaluation period. Of course, the two accept and board his helicopter, where there are two others waiting: Ian Malcolm, a scientist of chaos theory, and one of Hammonds lawyers. The helicopter escorts the crew to the small island, privately owned by Hammond, and upon landing Sadler discovers a plant species that has been extinct for millions of years.
Their amazement is doubled when the jeep they are driving in is greeted by a friendly brachiosaurus: a dinosaur. Welcome to Jurassic Park, Hammond proposes as everyone faints from their astonishment. Upon their rrival to the interpretive center, Hammond is greeted by his grandchildren, Tim and Lex- sent because of parental problems. To make the dinosaurs, Hammond has a crew of scientist excavate fossilized amber with remains of prehistoric mosquitoes that have dino blood and use that blood to get the building blocks of life, dino DNA.
With the mixture of the dino DNA and the DNA from frogs in Africa, the dinosaurs are made. Grant and crew take two little tour vans through the park, discovering the many dinosaurs that the park has to exhibit, including the dreaded T-Rex and velociraptors. Because the entire park is automated, except the xhibits, there are people to keep up with the running of all the electrical fences and vehicles-one of these people is Dennis Nedry. Nedry is hired to obtain several dinosaur embryos for a large corporation who would like these little gold mines. In order to maintain this goal he has to shut down all of the parks power.
In the mean time, because of the lack of dinosaurs in the exhibits, Elly travels out of the vans and ventures down a path where lies a sick triceratops. Elly stays behind with the vet and everyone else gets back into the vans. Back near the T-Rex exhibit, the power is shut off and Nedry breaks for the cold storage, eaving the tourists stranded near a highly dangerous animal who breaks from his enclosure and kills the lawyer, injurs Malcolm and strands Grant with Tim and Lex: in another area of the park, Nedry takes his embryos to his jeep and heads for the docks, but looses control and gets killed by a dilophosaurus.
Grant and kids make their way back to the interpretive center, and discover that the dinosaurs are breeding. Malcolm gets taken back with Sadler to Hammond where they turn the power back on and reunite with Grant, Tim and Lex. The group escapes the island and plan to destroy it.