In the film, Steve Lopez is portrayed as divorced. However, his real life counterpart remains happily married. Lopez said that while having himself portrayed as recently single in the film was a bit weird, it was much more important to him that the film makers captured the themes of his articles rather than absolute facts.
Most of the homeless people shown in the film are actually homeless.
The film makers shot on "skid row" in Los Angeles, which is known for being home to one of the largest stable populations of transient persons (homeless) in the United States.
Cameo: [Nathaniel Ayers, Jr.] The subject of the movie is himself seen in the front row of the concert, during the last scene of the movie.
In the scene that Nathaniel Ayers and Steve Lopez attend a rehearsal concert, all the seats are covered with canvas. This was not cinematic imagery; this is actually done in some concert halls during rehearsals to reflect a more accurate sound as if the seats were being occupied.
The real Nathaniel Ayers was invited to view the filming of the scenes at Disney Hall in Los Angeles, but opted on the day to set up his cello and music across the street and continue playing saying "I really got something going here. I think I'm going to stay and play this just a little bit longer." Steve Lopez spoke about this incident in an interview conducted by Dave Davies for National Public Radio's program Fresh Air in April 2008. He added: "I look(ed) across (the street from Disney Hall) and there he is sawing away, as he calls it. And inside this building there are maybe three hundred people, the LA Philharmonic, the cast, the crew, are shooting a movie about his life. And I said to the producer Gary Foster 'You know what Gary, we picked the right name for this thing, The Soloist. There he is.'"
As of April 2009, Nathaniel Ayers "has a girlfriend and is doing reasonably well" according to Steve Lopez. He is also taught himself to play the flute.
Despite his distrust of two-dimensional images, Nathaniel Ayers did attend the premiere of this film in Los Angeles with his family, who flew in for the occasion. He rarely watches movies or television.
Several members of the Lamp Community, a housing and care center for the mentally ill, appeared in the film and attended the Los Angeles premiere and after party. Nathaniel Ayers is a resident and beneficiary of Lamp.
Originally planned for a November 2008 release date, the film was held back due to Paramount's tightening of the number of films it releases per year and released late April of 2009. The trailer continued to run in theaters with November as the release date.
This is the second time Robert Downey Jr. has portrayed a real-life reporter. He previously portrayed San Francisco Chronicle reporter Paul Avery in Zodiac (2007/I).
Graffiti of the repeated phrase "I like myself" can also be seen behind Edward Norton in a promotional photo for Fight Club (1999)).
Lorraine Toussaint (who played Mr. Ayers' mother), Lisa Gay Hamilton (who played Mr. Ayers' sister Jennifer), and Nelsan Ellis (who played LAMP director David Carter) are all real-life graduates of The Juilliard School's Drama Division. Mr. Ayers was a student in their prestigious Music Division.