The episode was written by Michael Crichton, adapted from a screenplay he originally wrote in 1974, and directed by Rod Holcomb.
The episode was a critical and commercial success, receiving both high ratings (23.8 million viewers on its initial broadcast.
At Chicago’s County General Hospital, ER chief resident Dr. Mark Greene, asleep in an exam room, is awoken to tend to the drunk Dr. Doug Ross.
The inexperienced Carter manages to treat a woman with a hand laceration, and a man with anger issues who shot himself in the leg.
At his appointment, Greene finds the affluent private practice much calmer than the chaotic hospital, but despite the offer of better pay and less stressful hours, he is unconvinced to leave the ER.
They receive an urgent call and return to the ER to find Ross and most of the staff waiting by the ambulance bay doors.
However, when Crichton informed him of a book he was writing about dinosaurs, which would go on to be the 1990 novel, Jurassic Park, Spielberg shelved "ED" and worked on adapting the novel into the 1993 feature film of the same name.
Warren Littlefield, head of NBC Entertainment at the time, liked the project, but there was much debate and controversy among other executives at the network, who were dubious about the nature of the story as well as the number of characters and parallel subplots that they were worried audiences wouldn't be able to follow.
[3] Wells contacted previous collaborator, Neal Baer, a qualified doctor, to update the script as a lot of the medicine had become outdated in the almost two decades that elapsed since it was written.
The pilot was greenlit only five weeks before shooting had to begin if the episode was going to be made in time to enter the fall schedule.
John Frank Levey, the casting director, met with Clooney who read one single scene for the part of Dr. Doug Ross.
He was initially reluctant to audition as he was intending to take a break from acting to focus on directing, but was convinced by his wife and agent at the time.
His manager pushed back the feature film he was attached to direct in order for Edwards to be available to shoot the pilot.
Wells was impressed by actress Sherry Stringfield in NYPD Blue, and when she decided to leave that show he asked her if she would be interested in another project.
Unaware that the lengthy script was actually a television pilot and not a feature film, he went to audition for the role of Dr. John Carter.
Wyle's final audition was against Raphael Sbarge, the producers original choice for the role, but he won them over with his performance.
He then faced the challenge of learning his lines, many of which were long monologues filled with medical jargon, in less than a day before he was required on the set for shooting.
Julianna Margulies was cast as the part of nurse Carol Hathaway originally for the pilot only, after producers saw her guest appearance in another NBC show, Homicide: Life on the Street.
Margulies chose the role on ER and therefore the following episode reveals that Carol did not die and is at home recovering.
Crichton's screenplay was virtually unchanged from its original version, other than the fact that Dr. Susan Lewis became a female and Dr. Peter Benton became African-American and roughly twenty minutes of content was removed in order for the episode to be shown in a two-hour slot on television including commercial breaks.
The first episode ends after the scene in which Dr. Lewis talks to the patient who has lung cancer and shows him the X-ray, along with a "To be continued" subtitle.