George A. Romero had originally planned for all the zombies to perish in a massive explosion when they stumbled across explosive chemicals in the laboratory. Meanwhile, one of the crew members who had died during the attack was to have stayed dead and not come back as a zombie, thereby giving hope to the survivors.
The original script, for which George A. Romero couldn't get budget for, involved the scientists living above ground in a fortress protected by electrified fences and the military living safely underground. It also involved a small army of trained zombies, and the conclusion to the trilogy more brutal than the released version. This later became the basis of Land of the Dead
All the extras who portrayed zombies in the climax received for their services: a cap that said "I Played A Zombie In 'Day of the Dead'", a copy of the newspaper from the beginning of the film (the one that says THE DEAD WALK!), and one dollar.
The first scene (abandoned city) of the movie was filmed in Fort Myers and Sanibel Island, Florida. The theatre shown in the opening is the Edison; Thomas Edison used to summer in Ft. Myers and his house there is a tourist attraction.
The budget for George A. Romero's original script was estimated at $7 million, but he would only be given the money if he could film an R-rated film. He was told that if he went ahead and shot an unrated film with no limits on gore, the budget would be split in half to $3.5 million.
The underground facility was not on a soundstage. It was shot in the Wampum mine, a former limestone mine near Pittsburgh, that was being used for a underground storage facility. The 2,500,000 square foot mine is now operated as the Gateway Commerce Center who now called it a "subsurface storage facility".
In the scene change right after Logan tells the zombie that it needs to sit in the dark and think about what it did, and punishes it by turning off the light, a little bit of the "The Gonk" music from Dawn of the Dead can be heard in the scene change.
In the cafeteria scene, William McDermott (Jarlath Conroy) says that "All of the shopping malls are closed." This is a clear reference to the film's predecessor Dawn of the Dead, which is set in a shopping mall.
There is a debatable scene in the film where Bub the zombie may or may not have another line of dialogue. When Sarah enters Logan's lab, she is startled when Bub emerges from the shadows behind her. After this, he moans something that some fans believe is, "I'm sorry."
During a holiday break in filming, makeup artist Gregory Nicotero used the realistic and gruesome model of his own head (as seen in a laboratory scene in the film) to play a practical joke on his mother.
The blood and entrails used in the disemboweling of Capt. Rhodes were real. Pig intestines and blood were procured form a nearby slaughterhouse and used to make the scene. During filming the refrigerator housing intestines and blood was unplugged by custodial staff, and the entrails started to spoil causing most of those involved to become physically sick.
British band Gorillaz have sampled several audio clips from both Dawn of the Dead and Day of the Dead: portions of the music and some dialogue ("Hello? Is there anyone there?") from the latter feature in the track, "M1 A1", on their 2001 debut album; and some of Bub the zombie's grunts appear alongside sound-clips of the news reporters from Dawn of the Dead on one of their B-sides, "Hip Albatross". Furthermore, part of the score from Dawn of the Dead is used in the intro track on the 2005 album, 'Demon Days'. This album also features a track narrated by Dennis Hopper, who portrayed Kaufman in George A. Romero's sequel that year, Land of the Dead.
Dr. Logan figures that the ratio of the undead to the human survivors is 400,000:1. When the film was made, in 1985, the population of the United States in our universe stood at about 240 million. If Dr. Logan is right, and the US population of this universe stood at roughly the same, and this film took place in 1985, there are 600 living human beings left in the USA. However, since the history of the universe in the "of the Dead" movies had radically diverged from real world history even before the ghouls emerged (notice the Venus probe in the first movie), the timeline of the "Dead" movies remains unclear (the Stephen King novel 'Salem's Lost appears in this film, even though in the real world it came out in 1975; note that the first film in this series came out in 1968; Diary of the Dead, set simultaneously with the events of Night of the Living Dead, features technology not available in 1968 in our world), and we do not know how long after the ghouls emerged that this film takes place, one cannot easily presume that this film takes place in 1985 or that the US population would have remained the same.
Some of the headlines from the newspaper that says "The Dead Walk" appear to be: "Vice President Declares State of Emergency," "Whereabouts of President Unknown," "Food Supply Dwindles" and "Man Bites Man."
The Zombies who attack and feast on Captain Rhodes are played by Hermie Granati, David Granati, Joey Granati, and Rick Granati of the Pittsburgh rock band, The Granati Brothers (otherwise known as G-Force).
The "Day Of The Dead" love ballad song, "The World Inside Your Eyes" which appeared at the end credits of the movie was sung by Sputzy Sparacino (who was the lead singer and guitarist of the R&B/Dance/Cover band Modern Man at that time) and Gospel singer Delilah.
Sarah, John, McDermott, Miguel, Dr. Logan, Bub, and of course Captain Rhodes were the only characters from George A. Romero's original script that made it to the final version.
The music and songs for the movie soundtrack were composed by three great talented musicians. Including John Harrison (who played Bass for the late great, legendary Blues/Rock Singer/Songwriter/Guitarist Roy Buchanan), Jim Blazer (who was the original co-keyboardist of Modern Man. And who has now been popular for playing Piano, Hammond B3 Keyboards, and Organ for Spencer Davis Group since 1990), and the Crooner-Guitarist Sputzy Sparacino (the former Lead Singer and Guitarist of Pittsburgh R&B/Dance/Cover band Gigolo, who then was playing with Modern Man at that time). Talmadge Pearsall (who was the co-lead singer and keyboardist of Modern Man) only helped compose the song "The World Inside Your Eyes" ("Day Of The Dead" Ballad) with the three main Musicians/Music Composers of the movie.
During the end credits of the movie to the Love Ballad song "The World Inside Your Eyes", Sputzy Sparacino's first lead vocal part of the lyrics singing "Only you, only me. Here alone, all alone. It's our destiny. Plans were made. Now they've changed. Know what's right, know what's wrong. Life just rearranged. All we can do is to try and understand. I've given all I can. My future's in your hands. Come take my heart, my soul, my love, my life! Hold me tight, babe. Take me to the world inside your eyes. Take me to the world inside your eyes." never appeared on the end credits at the beginning of the song. It was instrumental for a minute until we heard Sputzy's band mates in Modern Man as the Chorus voices whispered singing "Eyes, Eyes, Eyes" and then co-lead Singer Delilah's vocal part of the song lyrics "Is it you? Is it me? Holding on for so long, trying desperately. Is it right or is it fair? Wanting more, so much more, and it's never there. I am with you when I feel like I'm alone. It's easy to pretend this world could never end. Come take my heart, my soul, my love, my life. Hold me tight, babe. Take me to the world inside your eyes. Take me to the world inside your eyes!" with the bandies of Modern Man singing their chorus parts "Tonight" could be heard near the very end of the song as the credits finally ended. But you can hear Sputzy's first lead vocal parts of the song on the soundtrack album itself. Then you can finally hear what the original recording sounds like.
The last time that George A. Romero and Richard P. Rubinstein worked together as a director/producer team. Romero wrote the scripts for Creepshow 2 and Tales From The Darkside: The Movie which Richard produced.
Although never confirmed, it has been rumored by fans that the character Joseph Pilato played in Dawn of the Dead is in fact Rhodes as a cop. Fans believe that Rhodes started out as a cop then later joined the army and became Captain. Since no passage of time is given in the dead films, it is very possible that years lapsed between Dawn and Day, making this scenario possible.
The second important "Day Of The Dead" Love ballad song, "If Tomorrow Comes" performed by Modern Man and sung by balladeers Sputzy Sparacino and Delilah again, never appeared in the movie soundtrack. It could be heard through some parts of the movie soundtrack only as an instrumental piece. But you can hear the original pop version of the song with the vocals of Sputzy Sparacino and Delilah singing it on the movie soundtrack album itself. You can also find and hear "If Tomorrow Comes" on Sputzy's solo artist albums "Not Just Any Love Song" (released in June 1, 1994) and "Too Much Too Soon" (released in August 17, 1994).
Taso N. Stavrakis:
In 2 roles: Appears as a Cave Zombie who gets bashed on the head with wood by Sarah. Referred to as Knock-On-Wood Zombie. He also appears as a Biker Zombie as the Zombie battle begins.
Akram Midani:
The former Dean of Fine Arts in Carnegie Mellon appears as a Fisherman Zombie pursuing Steel through the Mines. (You can see his wife Watfa Midani right next to him as another Zombie.)
George A. Romero:
As a zombie pushing a cart in the foreground during the final zombie feast, seen from the waist down and identified by his trademark plaid scarf wrapped around his waist.