In 1974, he wrote a pilot script for a medical series, " 24 Hours", based on his book Five Patients, however, networks were not enthusiastic. Odds On is a 215-page paperback novel which describes an attempted robbery at an isolated hotel in Costa Brava in Spain. During this time, he accompanied his longtime ship mate Rygel back to Hyneria in the former Dominar's attempt to unseat his cousin Bishan from power. Crichton was invited to testify before the Senate in September 2005, as an "expert witness on global warming".

His third John Lange novel, Easy Go (1968), is the story of Harold Barnaby, a brilliant Egyptologist who discovers a concealed message while translating hieroglyphics informing him of an unnamed pharaoh whose tomb is yet to be discovered. During his clinical rotations at the Boston City Hospital, Crichton grew disenchanted with the culture there, which appeared to emphasize the interests and reputations of doctors over the interests of patients. D'Argo was named after their fallen comrade Ka D'Argo and was born during the final battle of the Peacekeeper/Scarran War.He went to Scorpius and made a deal to give Scorpius everything he wanted about wormholes in exchange for Scorpius' help freeing Aeryn.

In 1990 Crichton published the massively successful science-fiction thriller Jurassic Park, which grimly envisions the human resurrection of the dinosaurs through genetic engineering. The original Crichton's obsession with locating Aeryn caused quite a bit of friction with this reality's family and friends, including the still living D'Argo and Zhaan. Then the surviving Crichton, at the urging of the dead Crichton via a deathbed message recorded by Stark, formulated a dangerous and risky plan to stop Scorpius from utilizing the wormhole knowledge he obtained from the neural chip, completing the job begun by the dead Crichton.The novel would prove a turning point in Crichton's future novels, in which technology is important in the subject matter, although this novel was as much about medical practice. Later this hope took second place to his love for Aeryn and this central relationship became a driving force for him and Aeryn. It seemed that his pop culture laden references were a way of putting his unfamiliar surroundings into perspective, giving something he didn't recognize a comprehensible label. The book follows each of five patients through their hospital experience and the context of their treatment, revealing inadequacies in the hospital institution at the time.

Crichton's 1992 novel Rising Sun delved into the political and economic effect of Japan–United States relations. True to his appearance, however, Futuro's intellect was superior to that of his "original template". She was shot by Scorpius as they fled and later died aboard Moya, shortly after John admitted that he could have grown to love her. Peter Doran, author of the paper in the January 2002 issue of Nature, which reported the finding referred to above, stating that some areas of Antarctica had cooled between 1986 and 2000, wrote an opinion piece in the July 27, 2006, The New York Times in which he stated "Our results have been misused as 'evidence' against global warming by Michael Crichton in his novel State of Fear. As a result, she requested John to marry her, ensuring the royal line continue with Katralla and not pass to her Scarran-collaborating brother.

It seems that there was also a real Karen Shaw whose identity John mixed up with Chiana's, whose alien appearance he believed to be a costume.

The technophobic antagonist of the story found it odd that a person would paint numbers as they were inorganic. The real Crowley, also a Yale graduate, alleged that by including a similarly named character Crichton had libeled him.According to Pat Choate, Crichton was a supporter of Reform candidate Ross Perot in the 1996 United States presidential election. With little choice thanks to Scorpius, Crichton married Katralla and was turned into a statue, planning to stay that way for 80 cycles. Steven Spielberg learned of the novel in October 1989 while he and Crichton were discussing a screenplay that would become the television series ER. In addition, chaos theory and its philosophical implications are used to explain the collapse of an amusement park in a "biological preserve" on Isla Nublar, a fictional island to the west of Costa Rica. A 2003 film based on the book was directed by Richard Donner and starring Paul Walker, Gerard Butler and Frances O'Connor.