The scenes in the "past" when Dean and Cindy are falling in love were shot first, in three weeks. After this, Ryan Gosling and Michelle Williams spent a month together in a rented house to age themselves in preparation for the "present" scenes. They spent a lot of their time grocery shopping, cooking dinner and learning to pick fights with each other.
The film was originally set to shoot in spring of 2008, but it was delayed due to Heath Ledger's death. The producers and director delayed the film out of respect for Michelle Williams, Ledger's ex-girlfriend and mother of his daughter Matilda, rather than going ahead and shooting the film with another actress in Williams' role.
According to director Derek Cianfrance, after shooting the first part of the love story, there were serious discussions about not doing the second part, retitling the movie simply "Valentine," and make it a depiction of falling in love.
When filming the argument scenes, director Derek Cianfrance gave instructions to Michelle Williams and Ryan Gosling individually, without the knowledge of the other, in order to create more tension between Dean and Cindy. For Williams, Cianfrance would instruct her to try to leave the room, use any way to break out of the argument with Gosling, etc. For Gosling, Cianfrance would tell him to use any means to persuade, get Williams attention, etc. Gosling stated it was a new and interesting process as it became a tug game on set.
Michelle Williams, Ryan Gosling and Faith Wladyka actually lived together in a house in Carbondale, Pennsylvania, for thirty days while filming Blue Valentine (2010). They struggled with the real stresses of having to share a bathroom and do the dishes three times a day. Their grocery budget was based on Dean's salary as a house-painter and Cindy's a nurse, $200 every two weeks. Gosling stated that it was hard for him and Williams to take off their wedding bands when it was over.
The inspiration for the film was the divorce of director Derek Cianfrance's parents when he was twenty years old. He was so devastated that he wanted to do a film that would help him figure out how a relationship began and ended.
Michelle Williams was first attracted to starring in Blue Valentine (2010) because she liked the script. Just before shooting began, director Derek Cianfrance told Williams that he was no longer interested in sticking to the script, and that he wanted Williams and co-star Ryan Gosling to improvise their scenes. This unnerved Williams, but Gosling said he did not mind improvising as he had trouble remembering his lines.
For the scene where Ryan Gosling and Michelle Williams sing and dance in front of the bridal boutique, director Derek Cianfrance told them to keep their talents hidden from each other so that when they improvised the scene, their revelations to each other would appear spontaneous.
Michelle Williams committed to the movie in 2003 and Ryan Gosling committed in 2005. Since those moments, director Derek Cianfrance never wanted anyone else for the roles. Cianfrance met Michelle Williams in 2003 and she read the forty-second draft of the script. She was so passionate about the film that Cianfrance immediately felt that it had to be her in the film. However, he could not get the film financed back then, so he had to wait.
Director Derek Cianfrance accelerated the relationship's corrosion by starting off-screen fights between the actors while they were living together. One night, he told Ryan Gosling to go into Michelle Williams' bedroom and try to make love to her. Gosling, soundly rejected, ended up sleeping on the couch.
Director Derek Cianfrance spent twelve years making the movie; he started working on the script in 1998. During that process, Cianfrance said that he wrote about sixty-seven drafts, mostly each one containing content added/modified based on on-set improvisations, inspirational encounters, etc., while he worked on several documentaries to secure more funding for the movie.
Steinway Moving and Storage was an actual company and was selected to participate in the film. Ryan Gosling actually worked and conversed with the company's employees. The owner, James "Jamie" Benatti, played himself.
The first scene shot was the flashback where Ryan Gosling goes to Michelle Williams' parents' house for dinner. Director Derek Cianfrance set the camera far back in the hallway beyond the back of the front door to capture how Gosling and Williams interacted, and he was impressed with their chemistry on film.
Ryan Gosling claimed that his approach to the role of Dean was living the character's life for the duration of production, including working on house paintings. He pointed out that Michelle Williams had the much harder task of leaving character at the end of the day so she could be a mother to her young children.
Director Derek Cianfrance had set the film in numerous places during script rewrites and redrafts including Florida and Hawaii. He finally decided on New York when Michelle Williams became involved so that she could go home and see her daughter.
When it came to casting Dean and Cindy's daughter, director Derek Cianfrance asked Michelle Williams whether she could use her daughter, Matilda, to play the role. Williams considered briefly, but after noticing that her child's interest laid beyond acting (she was quoted that Matilda's main hobby was horse riding), Williams declined.
The MPAA originally rated the movie NC-17, but after public allegations of using a double-standard to rate portrayals of sex on-screen, the organization agreed to hear an appeal. Upon review, the MPAA unanimously agreed that the film should receive an R rating. Had the appeal not been granted, it is possible that this would have been the first NC-17-rated film to get an Academy Award nomination since Henry & June (1990), and the first for acting.
The film's much-talked about sex scene was shot in the cramped bathroom of a real love motel in King of Prussia, Pennsylvania, using two long-lens cameras, one following each actor as closely as possible. The violence of the edits between their spaces shows how far apart they have fallen.
The past scenes were shot entirely with a hand-held camera and often in just one take, director Derek Cianfrance said, to create space around the characters and allow them to come together to fill the frame.
In 2015, Rachel Weisz revealed to The Playlist that at one point, she and Jeremy Renner were supposed to be in this movie but it did not work out for either of them. Weisz would finally work with director Derek Cianfrance in The Light Between Oceans (2016).
Cindy tells Dean that he has potential in life because of his artistic talents. The argument about potentiality was based on a talk between director Derek Cianfrance and his wife about getting the film made for many years.
Some have speculated that Dean and Cindy ended their marriage. One of the photos during the end credits shows Dean and Cindy running backwards holding a sign with "Is This You?" on it, hinting the upcoming dissolution of their marriage.