Lupita Nyong'o had a fear of cats and even asked Michael Sarnoski to replace the animal she was supposed to interact with. When he declined, she underwent exposure therapy. She said she had been terrified of cats, unable to be in a room with one and wary of them, almost certain they were out to get her. Because she was determined to play Sam, who owns a cat, she decided to face that fear. They hired someone to bring cats to her in Los Angeles; over several days she observed them and asked lots of questions, and when she felt brave enough she touched one, then two, until she was stroking them and able to hold a cat without panicking. She conquered her fear and later went on to adopt a cat of her own.
Patsy's Pizzeria in Harlem is commonly credited with having originated New York-style pizza.
The feline Frodo was portrayed by two cats called Nico and Schnitzel.
Henri, played by Djimon Hounsou, assists Eric and Frodo aboard the ferry to safety. Since Henri is depicted in Hiljainen paikka osa 2 (2020) as living on an island free from the creatures — at least until that film’s conclusion — it is probable that Eric and Frodo are likewise on the island, living in peace.
The vast majority of sequences set in New York City were filmed in London. The film's crew constructed a makeshift recreation of the Chinatown area of New York City on a London backlot to shoot most of the opening scenes, and numerous scenes set on the New York City subway were captured in several disused London Underground stations and tunnels. The one principal scene actually filmed on location occurs outside one of the film's few named places: Patsy's Pizzeria in Harlem. The remainder consists largely of second-unit & VFX work.
Lupita Nyong'o said the most enjoyable and thrilling part of the film was discovering how to convey meaning without words, since even the tiniest gesture of body language could alter the whole scene’s context, so each scene demanded considerable internalising.
At the puppet theatre after the opening attack, someone listening to a radio marks various locations on a globe. Newspaper clippings from the first film and a television news bulletin in the second film similarly make clear that the issue is worldwide.
Each instalment in the series is set in a different kind of populated environment. The first is set on a rural farm. The second unfolds at a factory and in a suburban neighbourhood. This instalment is set in an urban city.
One stretch of Churchill Place in Canary Wharf, London, stood in for New York City in a scene. Several badly damaged cars bearing New York, Connecticut and Florida licence plates, together with heaps of concrete and metal debris, were scattered along the stretch.
While browsing titles outside a bookshop, Sam is pictured holding a copy of Dawn by Octavia E. Butler. Butler is widely recognised as one of the foremost Black female science-fiction writers, and the novel centres on an alien invasion.
Joseph Quinn kept the card trick under wraps from Lupita Nyong'o until the day of filming, in order to capture her authentic reaction.
Jeff Nichols was originally slated to direct, but was withdrawn from the project owing to his commitment to another Paramount science-fiction production.
Paramount had initially intended for Frodo the cat to be computer-generated, but Michael Sarnoski insisted on using a live animal.
The helicopter announcements (voiced by Joshua Noble) were initially recorded in a variety of languages as a joint effort with director Michael Sarnoski to mirror New York City's multicultural make-up.
Alex Wolff, who portrays Reuben in this film, previously appeared in Pig (2021), which was directed by the same filmmaker, Michael Sarnoski.
The terminally ill Sam was conceived because Michael Sarnoski wanted a lead character who harboured mixed feelings about death.
The events in this film are set one and a half years before those of the preceding instalment, A Quiet Place Part II (2020).
Michael Sarnoski has acknowledged Alfonso Cuarón's Children of Men (2006) as an influence on the film's visual style and atmosphere.
John Krasinski personally chose Michael Sarnoski to direct this prequel, having been greatly impressed by the emotional depth Sarnoski brought to his film, Pig (2021).
In subsequent interviews, Michael Sarnoski affirmed that Eric's character is gay.
Principal photography took place over the course of two months.
Denis O'Hare was cast in an unspecified role that was later omitted from the film's final cut.
In a 2024 interview with A.Frame, Michael Sarnoski described his method for tackling a big-budget film: "Early on, Pat Scola and I sat down and made a shot list for the entire film, just as we did on Pig (2021). We aren't keen on the approach of rigging five cameras and trying to catch a large action sequence from five different angles. We planned very specific shots for every sequence. In some respects that can make things tougher because it leaves you with less to work with in the edit. But in other respects that method lets you be exacting and careful with how you use your resources, so you aren't wasting time or money on things you don't need. Essentially, we tried to approach this as if we were making a small indie film, asking, 'We now have the means to do whatever we want — but what do we actually want to do?' At times that can feel numbing, because the answer might be, 'Well, we could do anything!' Yet you have to keep asking yourself, 'Yes, but what should it be?' I think that question, in some ways, added pressure to really work out how each scene should be filmed. And to me, that's the most enjoyable part. Putting constraints around something is how you begin to find a film's identity."
