Languages spoken in the film are English, French, Italian, Mandarin, German, Russian, Latin, Armenian, Sanskrit, Egyptian (not Arabic), Babylonian and a little Romanian. The ancient Sanskrit, Egyptian and Babylonian are authentic, researched in ancient texts and manuscripts by a team of expert linguists. The film also includes an artificial, "made-up" language, done with such integrity that it could provide the rudimentary basis of a new language.
The first assembly put up by associate editor Corina Stavila and her assistant Andrei Dascalescu came in at about 3 hours and 30 minutes. The next cut brought that down to 2 hours and 50 minutes. This version was trimmed a further 30 minutes, including restoring 10 minutes of scenes that had been cut; resulting in a length of 140 minutes. However, the target was to bring in the film at two hours, therefore In September 2006, editor Walter Murch worked closely with director Francis Ford Coppola to get the cut down to two hours. An early version contained for example a sub-plot, also included in the novella, featuring the 1938 student radicals and the secret police associating Dominic with them. This sub-plot and other scenes were ultimately dropped upon suggestion by Murch in order to keep the story more personal and reaching the intended two hour goal.
Shot with two of Francis Ford Coppola's own Sony HDW-F900 CineAlta HD cameras. The signals from both F900s were recorded onto an HDCAM-SR field recorder in the HDCAM SR format. By sending the uncompressed, full raster 4:2:2 signal from the camera to the SR recorder, the team was able to preserve more of the camera's inherent image quality. In addition, the SR deck features the unique ability to record two simultaneous 4:2:2 A and B camera inputs onto a single tape. These recordings became the equivalent of the film negative and were used for the final digital intermediate. The onboard HDCAM tapes were used as back-up tapes for reviewing footage and to create DVCAM copies for ingest into the Final Cut Pro editing station. Coppola shot his next films with the same HD cameras and a similar workflow.
Dominic (Tim Roth) has James Joyce's avant-garde book "Finnegan's Wake" (1939) in his hotel room in Geneva and seems to read it. With this obvious reference to Joyce's most experimental work director/writer Francis Ford Coppola gives the audience a clue how he wants his film to be seen. However, it is still plausible that Dominic would read such a book at that time and place: The date given by Dominic in the film is the 7th May 1941; Joyce died in Switzerland on the 13th Jan. 1941. Therefore Dominic could have read about Joyce's death in the newspapers and simply decided to buy his last novel.
Francis Ford Coppola on shooting and finishing Youth Without Youth (2007) in Romania: "It's a country with a fantastic intellectual tradition - theatre, poetry, cinema - and right now it's going through a renaissance in cinema. Their films are winning awards all over the world and everyone under 35 speaks English. They're very well educated and it's a very cinema-friendly country, but they're lacking in the visual effects department and other areas. We did the post in Bucharest and Walter Murch came over to edit and help oversee all the post. (...) The great thing about post now is that digital cinema has become a reality, so a filmmaker has more ability to compose picture and sound than ever before, and all because of these new tools, such as the latest editing systems like Final Cut Pro, Pro Tools and so on, which are also becoming less and less expensive." [Feb.2008]
Francis Ford Coppola said that Youth Without Youth (2007) was one of the five best experiences doing a film in his life. He is very fond of the results: "Yes, I was very pleased with it, and of course I was working with my longtime collaborator Walter Murch, and I think the film is really beautiful in the way it looks and was edited and the music and everything." [Feb.2008]
Francis Ford Coppola wanted the production to be so small that all the equipment could be carried in one van, just like they did it on his road movie The Rain People (1969): "We went back and built this truck again - a more modern version, but still one truck." 
Francis Ford Coppola on Mircea Eliade's novella (1976): "I knew it was an unorthodox story but I thought it was so full of craziness and energy... I felt it was like an adventure reading it, so I wanted to make a film that would be like that." 
Unlike the other characters, Prof. Giuseppe Tucci (played by Marcel Iures) existed in real-life (5 June 1894 - 5 April 1984): He was an Italian scholar of oriental cultures, specializing in Tibet and the history of Buddhism. He was Italy's foremost scholar of the East, with such diverse research interests ranging from ancient Iranian religion to Chinese philosophy. He taught primarily at the University of Rome but was a visiting scholar at institutions throughout Europe and Asia.
Production started in Bucharest, Romania, in October of 2005 with Francis Ford Coppola's team working out of a rented Romanian villa that served as a combination of production offices, post and living quarters. The house was used for over a year. Editor Walter Murch joined the team in April 2006, along with Sean Cullen, his long time first assistant and associate editor; Kevin Bailey, a post-production intern; and Pete Horner, the sound designer and rerecording mixer. In September 2006, Murch worked with Coppola in Bucharest to get the cut down to two hours and a lock. The in-house approach carried through to finishing, as well: Part of the sound, even the mixing of the soundtrack album, was done in this villa.
The trivia items below may give away important plot points.
Matt Damon appears uncredited as a journalist/CIA agent in one scene and tries to convince Dominic Matei to work for the Americans. The casting of Damon is probably an intertextual reference to The Good Shepherd (2006), where Damon played a very similar character in a story partially set in the WWII period, too.
This is Francis Ford Coppola's first genuinely surrealistic film. Like in the long tradition of surrealism, the concepts of identity, time, space, consciousness and reality itself are presented as dream-like illusions. The film makes it impossible to know for sure where a dream or fantasy begins or ends. The whole narrative is ambiguous and nearly non-linear. The fantastical and farcical nature of the events presented, together with the eclectic mix of genre tropes and styles, create a dream-like effect and surreal humor. The film tries to create and represent a state of lucid dreaming for the audience.
Youth Without Youth (2007) has elements of a drama, a romance, a fantasy, a mystery, a spy thriller, a film noir, a World War II historical fiction, a science-fiction story, a farcical comedy, even of a superhero origin story. The genre of this film is nearly unclassifiable. This intentionally confusing mix of popular genres can be regarded as a surrealist and postmodern strategy. The marketing focused mostly on the romance and mystery aspects to sell the film.
André Hennicke plays a leading Nazi scientist who is a devoted follower of Adolf Hitler. Hennicke is best-known for his role as a Nazi General in Downfall (2004). His casting might be an intertextual reference to the other film.
The protagonist Dominic Matei is struck by lightning on Easter Sunday, ironically just when he had planned to commit suicide. Easter Sunday, also called Resurrection Sunday, is a Christian holiday celebrating the resurrection of Jesus Christ from the dead. Like Jesus Christ in the Bible, Dominic Matei is 'resurrected from the dead' and finds a new life.