During filming, the cast became obsessed with playing the murder game (a game in which one person, who is the murderer, has to find a subtle way to kill other players simply by looking at them without giving themselves away as the murder). This is very apparent in the dinner scene where everyone is sitting around the table. If you watch everyone's eye movements, it's obvious they are playing the game.
In a 2016 interview, Helen Mirren said she had never regretted not having children, except briefly when watching this film: "It was about the whole story of being a parent, and how it never stops, even when you're a grandparent. I realized I would never experience that, and for about twenty minutes, I sobbed for the loss of that, and the fact that I never experienced it."
Martha Plimpton was bald at the beginning of filming, because she had just finished Silence Like Glass (1989), in which she played a cancer patient. She wore a wig throughout filming, and a hairpiece, when Julie has a mohawk.
The film grossed just under one hundred million dollars during the original run in theaters. Several years later, the project was re-released into theaters, so it could be logged officially as earning one hundred million dollars.
According to the interview in the DVD extras with composer Randy Newman, the soundtrack song "I Love to See You Smile", which is perhaps his most beloved, was written with Mary Steenburgen's smile in mind.
When Grandma (Helen Shaw) inhales the helium balloon and says that when she was born, Grover Cleveland was President. Shaw was born on July 25, 1897, just four months and three weeks after the end of Cleveland's second term.
As originally written, Karen would smoke a joint every night. Mary Steenburgen argued that this was out of character for a woman strong enough to confront her family's problems head on. The filmmakers agreed, and changed the script.
In the scene where Gil and Karen are going to Kevin's school to speak to the school principal, the school is Gerald Paris Elementary School, named as an homage to Jerry Paris, who directed 42 episodes of Happy Days (1974).
In the opening scene at the ballpark, the base runner has a decided limp, because he pulled his hamstring on one of the first dozen takes of the shot. The shot in the film, is one they settled on after approximately twenty takes, due to the fact that the hitter was unable to hit the ball into center field. The hitter was a college player, not a professional, as originally dictated to the casting department.
The porno tape that Helen discovers in Garry's closet is Blonde Goddess (1982). The clip shown is from the first scene - a parody of Indiana Jones. Adventurer 'Louisiana Smith' is attempting to rescue 'Jungle Jane' from a tribe in the Yucatán.
Joaquin Phoenix (he goes by Leaf in this movie); was homeless just a short time before he appeared in this movie. His family also belonged to a cult called the Children of God in the 1970s for a while. It was somewhere during this time they all changed their surname from Bottom to Phoenix.
The movie was filmed in central and northern Florida. The shopping center where the photo booth is standing is in College Park, Florida. The photo booth was constructed for the movie. The Showbiz Pizza is located in Altamonte Springs, Florida and is still there, except it is now (like all Showbiz Pizzas) Chuck-E-Cheese. Kevin's birthday party was filmed at The Mystery Fun House in Orlando, Florida.
In the scene where Steve Martin and Mary Steenburgen are fighting over the fact that she is pregnant, Steve says "Let's just have a dozen, and act like they are donuts." In Cheaper by the Dozen (2003), he plays the father of a dozen children.
In the opening scene Gil Buckman (Steve Martin) is reminiscing as his younger self at the ballpark In the background a peanut seller can be heard yelling out "Hot peanuts!". It's the voice of Steve Martin
Tom Hulce has a tendency to play crazy characters, wild characters, characters who are overly sexual, or heavy drinkers or who act out in some way. His performances in Animal House, Amadeus and Parenthood all bear that out.
There were two attempts to adapt this movie into a TV series. The first ran for only twelve episodes during 1990-1991. Although the characters all retained their names from the film, all actors but a handful of the children were recast; the adult leads were Ed Begley Jr. and Jayne Atkinson as Gil and Karen Buckman, and the show provided an early role for the then-teenaged Leonardo DiCaprio as Garry Buckman (the role originally played by Leaf / Joaquin Phoenix). The second TV series was a looser adaptation (for example, the main family's last name was changed to "Braverman") and much more successful than the first; it started in 2010, ran for six seasons, and starred Lauren Graham, Peter Krause, and Dax Shepard.
The name of the school that Kevin attends, and where Gil and Karen go for the meeting with the principal, is Gerald Paris Elementary. Jerry Paris directed 237 episodes of Happy Days (1974), which also starred Ron Howard.
Dianne Wiest (Helen) was in The Lost Boys (1987), which was directed by Joel Schumacher who also directed Batman Forever and Batman & Robin (1997), Joaquin Phoenix (Garry) would play Batmans nemesis, The Joker in the DC movie of the same name Joker (2019) thirty years later.
Joaquin Phoenix's character Garry carries around a paper bag filled with pornographic films. Ten years later, he would star in 8MM (1999) as an adult film store clerk with access to hardcore pornography.