In the opening credits, when Louie is in the pizzeria, a passerby can be seen extending his middle finger at the camera. This was not planned. According to C.K., he saw this as good sign that the show would get picked up and he decided to leave the finger in the opening.
The series only shoots for three days per week. Louis C.K. has custody of his children for the rest of the week and refuses to shoot on those days. On those days, he edits the episodes while his children are at school. According to C.K., the crew dislikes the schedule but has to accept it.
Louis C.K. has said that continuity is not hugely important to his series, with each episode having its own "end goal". Louie's immediate family has been a major example of this. In Season 1, two different versions of his mother appeared (one a miserable, selfish old woman, and the other a kind and likable middle-aged woman) and he had a loser brother named Robert; in Season 2, his mom doesn't appear, and Robert no longer exists, having been replaced by two sisters (one a likable, tough, pregnant woman, the other a mentally disturbed mother of a sullen teenager) and Season 3's finale introduced another sister portrayed by Amy Poehler. Different actresses have also been used to play his daughters without any explanation.
Susan Kelechi Watson was cast as Louie's ex-wife even though she is African-American and Louie's children are Caucasian. Louis C.K. stated that he was so impressed by her audition that he cast her regardless of her race.
When writing the fourth season, Louis C.K. found himself writing so much of a story line that he ended up having more like a movie screenplay, about 180 pages. He decided to shoot it anyway and make into parts, resulting in the six-part "Elevator" episodes.
This show is currently the one exception to the intervention process from network executives. After a bad experience with HBO with his show Lucky Louie (2006), the comedian had no particular interest to return to TV and rejected offers from the networks. By his own admission, he made enough money with the stand-up tours and his duties as a divorced father prevented him from working half the week. John Landgraf, FX's president, met with C.K. and committed to work on his terms. To the actor, that meant absolute creative freedom, no control from the network whatsoever, no notes and only the money for the show. Without putting it in writing, Landgraf agreed to C.K.'s conditions, so the comedian receives $300,000 to make each episode and collects the minimum wage for DGA and WGA. He shoots on the days he is not in charge of his daughters, films on his own and sends the episodes to FX once they are edited, mostly by him. Therefore, the executives are watching them as another viewer and can not give notes.
The theme song, "Brother Louie", was a #1 US hit by Stories in 1973. Stories' lead singer, Ian Lloyd, sings the theme. The word "cry" was changed to "die" in the second repetition of the chorus at C.K.'s request. It was produced by Reggie Watts. Watts recorded a version but C.K. rejected it. It costs $5,000 per episode for the publishing.
The hiatus between season three and four was Louis C.K.'s own request. He said: "I want season four to go somewhere new. I'm looking back to when I did the first season and the time I took to do the show and decide which directions to go in and I want that back again. I want a little breathing room."
Louis C.K. has expressed his admiration for Woody Allen and his body of work several times. The show shares tone and style with Allen's movies, and C.K. even hired Allen's famous editor Susan E. Morse (until 1998) for the third season.