Director Jonathan Lynn talked about casting the role in the DVD commentary, “I was very eager to have Ralph Macchio in the movie, I must confess, I had never actually seen ‘ The Karate Kid’ .”
Lynn went on to say, “I watched him in a couple of videos that his agent sent and I thought he was just perfect for the part. … He’s very good in the movie.”
Launer Headed South for Some Script Research
In order to research the script, Launer decided to take a road trip through the South. He started off in New Orleans, continued towards Mississippi and Alabama, and finished by driving down the Gulf Coast. The trip ended up supplying tons of material for the script. His car got stuck in the mud, there were grits on every single restaurant menu, and he heard the ghostly cry of the screech owl for himself. He even found time to meet with the Butler district attorney, who reminded him a bit of actor Lane Smith. Therefore, it is no surprise that Smith was eventually cast as the DA in the film.
Another important thing that he experienced during his drive was the friendly attitude of the people. According to the bio, everyone “was very friendly and helpful, but when he told them he was making a movie that took place in the south—they’d get very concerned—afraid that Hollywood movies always made them look like bumpkins. That too [was] weaved into the story.”
Launer Wanted Robert De Niro to Play Vinny Gambini
When the script was completed, Launer held a casting meeting with the president, vice president, and CEO of Fox. He brought up the name Robert De Niro as his first choice for the part of Vincent LaGuardia Gambini. Launer later told Writer Unboxed , "the prez looked uncomfortable, embarrassed that I would suggest such an actor."
‘De Niro, uh … well … he’s not funny. And … his movies don’t make money.’ … Now … the only movies De Niro acts in that make money? Comedies! So, I feel vindicated. But I wish I could’ve been given a big fat check when I [ended up] being proved right.”
Vinny Was Based on Guys from Joe Pesci’s Neighborhood Growing Up
The actor, who grew up in New Jersey, later admitted that Vinny's character was based on people he knew when he was growing up.
In an interview with The Movie Show in 1992, Pesci said there were a lot of people like that in smaller neighborhoods, like the one he lived in, so he used these characters as inspiration for Vinny.
The Character of Mona Lisa Vito Was Almost Cut from the Movie by the Studio.
In an interview with Writer Unboxed in 2007, Launer revealed that the studio had initially wanted to get rid of the colorful character of Vinny’s unemployed hairdresser/car expert girlfriend. Launer was forced to add a scene, specifically requested by the studio president, to the second draft in order to keep the character in the movie. He said, "He wanted Vinny’s girlfriend to complain that he’s not giving her enough attention."
Launer said that he eventually, “figured out a way where they’d HAVE to keep her and embellished her character … she does complain, but at least apologizes for bringing it up, and you don’t hate her for bringing it up largely because it’s funny. … Now, I thought if she brought this up at this point where he is simply going through hell—he should be pissed off. And he is. So he kinda tears into her.” In the end, the scene which features Mona Lisa’s tirade about her “biological clock”, became one of his favorites in the entire script.