Industrialist John Hammond has brought to life a groundbreaking theme park, Jurassic Park, situated on the fictional Isla Nublar, located off the coast of Costa Rica. Following the tragic death of a dinosaur handler at the hands of a Velociraptor, the park's investors, led by lawyer Donald Gennaro, insist on getting expert opinions about the park's safety measures. Gennaro reaches out to chaos theory mathematician Ian Malcolm, while Hammond enlists the expertise of paleontologist Dr. Alan Grant and paleobotanist Dr. Ellie Sattler. Eager to fund his research for the next three years, Alan reluctantly accepts Hammond's generous offer to tour the park.
Upon their arrival, the team is in awe as they encounter a live Brachiosaurus for the first time. Inside the park's visitor center, they discover that the dinosaurs were cloned using DNA extracted from prehistoric mosquitoes preserved in amber, supplemented with frog DNA to fill gaps. To prevent breeding, all the dinosaurs were engineered to be female through advanced chromosome manipulation. Their intrigue deepens when they witness the hatching of a baby Velociraptor, with Dr. Henry Wu revealing alarming information about unauthorized breeding within the park.
Despite some initial skepticism, Gennaro becomes enthusiastic about the park. However, during lunch, the group engages in a heated discussion on the morality of cloning and genetic manipulation. Malcolm raises serious concerns, warning that despite humanity's ambition, the park is destined for failure, as dinosaurs had their chance and have been selected for extinction by nature itself. He cautions against the perils of humans and dinosaurs coexisting, separated by millions of years of evolution.
The tour takes an unexpected twist when Hammond's grandchildren, Lex and Tim, join the group. As their adventure unfolds, they encounter programming glitches and are interrupted by a looming tropical storm. Many park employees evacuate, but Sattler remains behind with the veterinarian to examine a sick Triceratops. Meanwhile, disgruntled programmer Dennis Nedry plans to steal embryos following bribery from corporate rival Dodgson. His treachery leads to security failures that leave the group stranded near the menacing Tyrannosaurus Rex enclosure.
Chaos ensues as the Tyrannosaurus escapes, attacking and injuring Malcolm while devouring Gennaro, as Grant, Lex, and Tim narrowly manage to flee. After a disoriented Nedry gets lost in a storm and ultimately meets his demise at the hands of a Dilophosaurus, Sattler rushes to the control tower to inform Hammond of the calamity.
Despite multiple encounters with danger, the team regroups to outsmart the ferocious Velociraptors that have been freed due to the power outage. As Grant, Tim, and Lex race against time, their ingenuity shines through when they devise a plan that involves reactivating the park's security systems with the help of computers. Ultimately, they restore power just in time to call for help from Hammond.
In a desperate bid to escape the island, the group faces off against the cunning raptors only to be saved by the sudden appearance of the mighty Tyrannosaurus. With Hammond arriving in a jeep alongside the injured Malcolm, the group hastily boards a helicopter, leaving the horrors of Jurassic Park behind them.