Stories from the set

In the comics, Ajak, Makkari and Sprite are men. In the film adaptation they were made women. These roles were played respectively by Salma Hayek, Lauren Ridloff and Lia McHugh.

According to actor Kumail Nanjiani, director Chloé Zhao prefers traditional filming over working with green screen technology.

For the filming, Kumail Nanjiani followed a strict diet and trained with Grant Roberts, a trainer and holder of the Mr. Canada title. Nanjiani worked out at a gym in Beverly Hills five days a week for 3 months to build muscle mass.

In November 2019, the film's cast and crew were urgently evacuated from the Canary Islands after an unexploded German bomb was discovered near the filming location.

Because of her deafness, Lauren Ridloff found it difficult to act in scenes where her character (Makkari) interacts with digitally created characters, or in action scenes. Angelina Jolie (who played Thena) helped her by using a laser pointer.

Lauren Ridloff's father coached the actors in the film in communicating in sign language.

According to producer Kevin Feige, Gemma Chan was cast in this film at his insistence. He very much regretted that in the sci-fi action film Captain Marvel (2019), in which Chan also appeared and which he produced, her talent had not been fully showcased, so he decided to work with her again on another project.

The circular ornament on the Eternals' garments is a reference to the astrolabe (one of the oldest astronomical instruments, used to determine the latitude and longitude of celestial bodies).

Actor Kumail Nanjiani wanted his performance in this film to combine the witty demeanor of John McClane, Bruce Willis's character from the Die Hard film series, with the looks of Bollywood actor Hrithik Roshan.

Actress Salma Hayek initially did not want to work with Marvel Studios, believing she would get a secondary role. Salma agreed to meet and discuss filming when she learned that director Chloé Zhao was working on the film.