The exteriors of Orlok's castle were filmed at Hunedoara Castle, also known as Corvin Castle, a Romanian castle located in Transylvania and one of the largest medieval castles extant in Europe.
According to Bill Skarsgård, his voice was the aspect of the part he worked hardest at, spending six weeks before shooting not doing "much else than just record myself". "And on set, I would keep doing these exercises. It sounds kind of like Mongolian throat-singing. It's [insane]."
The snow used in the movie is not computer-generated. Director Robert Eggers used a technique from the 1940s where frozen potato flakes are crushed and made into snow-like particles. The once-common practice of using snow candles to achieve fake snow effects has been banned on movie sets due to the fact that a toxic gas is emitted. Most people suggested using CGI, but Eggers refused and eventually decided on frozen potato flakes while watching old movies that used the technique.
Bill Skarsgård trained with an opera coach to lower his voice an octave to make the voice of Count Orlok as deep as possible.
In an interview with Variety, director Robert Eggers explained that the design for Orlok deliberately went back to folklore and to the culture of Orlok's home region, with his costume having very long sleeves, strange high-heeled shoes and a furry hat, as well as a mustache.
Robert Eggers: [folkloric, mythological, and fantastical period piece] A Bruxa (2015), O Farol (2019), O Homem do Norte (2022), and this film are period pieces that are based on folklore, mythology, and fantasy, which reflect through their atmospheres, settings, and environments.
Robert Eggers: [ominous-looking animals that haunt the main characters] In this film, rats, dogs, and wolves haunt, intimidate, and attack several of the main characters and background characters during most of the film. In A Bruxa (2015), farm animals such as goats, chickens, and rabbits haunt and intimidate the family. In O Farol (2019), seagulls constantly haunt and intimidate Thomas Howard throughout the film.
Robert Eggers: [a character named Thomas] In this film, one of the main characters' names is Thomas Hutter. In O Farol (2019), another Eggers film, two of the main characters' names are Thomas Wake and Thomas Howard. In Eggers' first feature film, A Bruxa (2015), the main female character's name is Thomasin. The name Thomasin or Tomasin is the feminine version of the name Thomas.
Robert Eggers: [Ralph Ineson] Ineson is a cast regular for Eggers. Eggers' other films, in which Ineson starred, are A Bruxa (2015) and O Homem do Norte (2022), respectively.
Robert Eggers: [Willem Dafoe] Dafoe is a cast regular for Eggers. Eggers' other films, in which Dafoe starred, are O Farol (2019) and O Homem do Norte (2022), respectively.