Friends and family members of the cast and crew often provided the names of the doctors paged over the PA system. In several episodes, Dr. Gwyneth Paltrow is paged. Her father, Bruce Paltrow, was the series' executive producer.
Actor William Daniels said that when he was offered the part of Dr. Craig, he was not only given the pilot script to read, he was given the first three scripts to read. He said producers did this to show that his character was prominent in some episodes but not others. Daniels said it gave him a sense of the ensemble nature of the show.
One episode called for Dr. and Mrs. Craig to visit Philadelphia. Inspired by returning to Independence Square, William Daniels sang a few lines of the song, "Sit Down, John!", from 1776 (1972). (The line was "It's hot as hell in Philadelphia!") The moment was included in the episode. (He also mentioned that there was something about being in the city of Philadelphia that just made him want to sing and dance). Daniels played John Adams in that movie. In this episode Dr. Craig (Daniels) also mentions to his wife that back in medical school he was "obnoxious and disliked" which is also something said by John Adams to his wife in "1776".
The writers of this show shared a building and a copy machine at MTM with the writers from Hill Street Blues (1981). Whenever they needed inspiration, they would look at a script from Hill Street Blues (1981) and that always pushed them to do better.
Norman Lloyd got one of the lead roles as Dr. Daniel Auschlander, because he was lifelong friends with Bruce Paltrow's family. He was supposed to guest-star in only 4 episodes, but with the connection of the show, along with some response from the audience, he stayed until the show's cancellation.
The orderly, Warren 'Cool' Coolidge, was also a character played by the same actor in The White Shadow (1978). In one episode we see him wearing his Carver High School varsity letter. In another episode, when an actor from "Shadow" played a different role, that actor was mistakenly referred to by his name from "Shadow". The actor corrected the "mistake" on camera.
In one episode, Dr. Axelrod and P.A. Luther Hawkins are trying to cheer up Dr. Fiscus, who had been shot. Among the things they perform to do that is blowing up rubber surgical gloves, then putting them over their heads, to no avail, prompting Axelrod (Stephen Furst) to make a comment about the guy on TV who got a big laugh on TV doing the bit - which was Howie Mandel, who played Dr. Fiscus.
The elevated train seen in the opening titles is the Orange Line of the Massachusetts Bay Transportation Authority, Boston's public transportation system. During the final season, the Orange Line was moved to an underground route and no longer ran on elevated tracks, thus making its appearance anachronistic.
The show was sued by Humana because of similarities between the company and "Ecumena", the company that took over St. Eligius in the show. The show eventually dropped the name and issued a disclaimer on each episode.
The facade for the hospital St Eligius is the Franklin House on East Newton Street in Boston. That building provides affordable for residents in the South End of Boston. From the early 1900s to the 1970s the building was the Franklin Square Hotel for Women. It provided apartments for young working women in Boston. For a few months after she graduated from Boston University in the early 1960s Faye Dunaway was a resident there.
The last episode is full of inside jokes, including a doctor named Brandon Falsey, a reference to Brand and Falsey, the creators of the show. There was a chase of a "one armed man" a reference to the Fugitive. During the chase, someone yells, "Move the gurney, Hal," a reference to Hal Gurnee, Dave Letterman's director.
All of Ed Flanders's anger, combined with his drinking problems, and thereby, having an unprofessional relationships with his co-stars, had led to his firing on St. Elsewhere (1982), at the end of the fifth season, but came back for the first two episodes of the final season, and for the finale.
The trivia items below may give away important plot points.
Based on the series-ending twist, the show is the center of what is known as the "Tommy Westphall Universe". The show had a crossover with Cheers (1982), and several characters were featured in Homicide: Life on the Street (1993). From those links, the program can be linked to at least 280 other non-animated shows, ranging from I Love Lucy (1951) to CSI: NY (2004) (as of 2007).
At the memorial service for Dr. Caldwell ('Mark Harmon'), who died of AIDS, Nurse Rosenthal commented that Caldwell always thought he was the sexiest man alive, which was a reference to Mark Harmon being named People Magazine's Sexiest Man Alive in 1986.
When the show was to be canceled after its sixth season, show writer Tom Fontana pitched several ideas for ending the series. One of them had two doctors in conversation, when they are suddenly interrupted by a nearby nuclear explosion that supposedly kills everyone; another one had one doctor confessing he was the second gunman during the JFK assassination, and then pulling the gun on his colleague. Executive producer Bruce Paltrow didn't like either idea, but he was receptive to Fontana's suggestion of the 'Snow Globe ending' which implies that the entire series occurred inside the fantasy of an autistic boy. According to Fontana, half the viewers accepted the ending, while the other half absolutely hated it.