The film was shot in 23 days and finished one day ahead of schedule.
Was originally made as the short film Gowanus, Brooklyn (2004), which won an award at the Sundance Film Festival. Shareeka Epps and Karen Chilton reprise their roles as Drey and Drey's mother. Matt Kerr, who plays the substitute teacher Mr. Light in this film, played Mr. Dunne in the original short.
Rachel McAdams, then Ryan Gosling's girlfriend, came to visit the set during the filming of the bar scene. As the production was running low on bar extras, Rachel hopped in to help out and make the bar look busy, but her scene did not make the final cut.
The Dan Dunne character was originally written to be in his mid-thirties. However, the filmmakers changed this to accommodate Ryan Gosling's age. Gosling was 25 years old at the time of filming.
(According to the filmmakers' commentary on the DVD) the film was shot hand-held, except for a short sequence in Dan Dunne's apartment. The sequence in Dunne's apartment happens when he is not there, and it contains all static shots. These static shots were shot on a tripod.