Blooper

When Ferris is running home, his shoes change from dress shoes (saying goodbye to Sloane) to canvas tennis shoes (running down the sidewalk) to running shoes (through his neighbor's house and back yard) and back to dress shoes (confronted by Rooney at the back door).

When Cameron first falls into the pool, his chair stays on the diving board; in the next shot it can be seen in the water behind him as he sinks. When Ferris dives in to save him, the chair is back on the diving board.

When Ferris and Sloane kiss goodbye, her fingernails change from short and unpolished to long and manicured.

Cameron's hair changes while talking to Mr. Rooney on the telephone.

When the Ferrari is being 'rewound', the rear car tires actually move forward. However, the car does go in reverse as intended after Cameron pushes the car loose until it crashes through one of the plate glass windows and falls into the ravine below.

In the end titles, "Star Wars (Main Title)" in incorrectly credited as "Stars Wars (Main Title)" with an extra 's' at the end of Star.

The 6500 RPM redline is visible, but that Ferrari model did not have a redline marking.

The parade in the movie is the Baron von Steuben Parade, which is a real event but takes place on a Saturday in September, when filming was done, not Spring when the plot is set. Even worse, plenty of school age children are in the audience, which makes no sense.

The dummy in Ferris' bed would not "sit up" when Jeanie flings the door open considering the way the string is attached (shown in earlier scene when mom peeks in on him).

When the Ferrari is on the jack to run the mileage back,it's an old style bumper jack used on American cars. it hooks on the car's bumper to lift it. it would never be used on a Ferrari's bumper,it would tear it off,or damage it. Most foreign cars came with scissors jacks,used under the frame.

The scene where Ferris, Cameron, and Sloane are in the hot tub/pool doesn't make much sense. Cameron's house is in the woods, while Ferris's and Sloane's backyard's are all grass. They are swimming at Cameron's. You can tell because when they're at Cameron's garage, Cameron's and Ferris's hair are still wet.

Edward Rooney mistakes the video arcade girl for Ferris because of the jacket, but Rooney has not seen Ferris that day so there is no way he would know what he is wearing. However, it would not be improbable or unusual for Ferris to wear the same jacket all the time.

Although the girls in the restaurant are playing a Karate Dô (1984) arcade game, the sound effects played are *not* from Karate Champ, but actually from Puckman (1980). Keep in mind that this was an arcade/pizza parlor full of arcade games, so there could've been a Pac-Man game there as well that this sound effect came from.

When Ferris' dad is in the car next to Ferris as they wait on the street, it shows Dad reading a newspaper that has a "Rally Around Sick Youth" article on the front page. Supposedly, there is no way the article could have made it to press in the middle of the day, let alone it being reported early enough to be printed for the same-day edition. However, a student gave a lengthy explanation of Ferris's absence due to being sick at Baskin-Robbins the night before. This "news" could've easily been reported and printed in time for the morning edition of the newspaper.

Chasing Ferris around Chicago would be the job of a truant officer, not a school principal. But Principal Rooney's behavior throughout the film shows that he is not mentally stable.

During the Economics class early in the school day, two of the bored students have watches showing the time to be approximately 6:25.

The movie takes place in spring, yet at Cameron's dad's garage, some of the leaves on the trees are changing color, as they would in autumn.

At the beginning of the movie, when it's about 7:00 or 8:00 in the morning, a clock in the high school hallway reads 1:40.

When Ferris, Sloane, and Cameron are driving home in the Ferrari, Ferris changes lanes but never turns the steering wheel.

At 43 minutes, when Sloane is sitting in the taxi with Ferris and Cameron on the floor, Ferris' dad is in a taxi next to them reading the newspaper. As the scene ends you can see the headline "Community Rallies Around Sick Youth", but the actual article is about a Chicago policeman who killed himself.

The movie is set in Spring 1986. However, during the parade scene, (around 58:09) a theater marquee is presenting Godzilla 1985 (1985) and Voglia di vincere (1985), which premiered in August 1985.

When Ferris starts the Ferrari in front of the school when collecting Sloane, its clear Ferris selects Drive on an automatic gearbox. However, when driving, the soundtrack is of a manual stick-shift gearbox.

Ferris is on the float and singing Danke Schön. The accordion player is neither playing the keys nor squeezing the bellows.

In the parade while Ferris is singing "Twist and Shout", several members of the marching band are not playing marching-style instruments.

In the initial sequence where Ferris is adjusting his stereo, the equalizer LEDs are moving in sync with the soundtrack indicating the song on the soundtrack is supposed to be what is playing in his room, but the power meters on the Carver M500t amplifier above the EQ do not move, indicating nothing is actually being played.

When Jeanie is speeding down the street, her mother is hollering at her but she is sitting still and appears to be perfectly calm.

When Cameron is sitting in his car deciding whether or not to go pick up Ferris, a crew member can be seen walking around behind the left side of the house.

After Ferris picks up Sloane and starts talking to the camera you can see the shadow of a crew member moving around on the car's door.

Late in the movie where Ferris races his parents home, an orange hook and protective tape are visible on the hood of the father's car as he drives behind the old lady. The hook was used to secure the camera onto the hood for filming.

A reflection of a camera can be seen in the handle of the fridge near the beginning of the film.

During the Chicago fly by at the start of the movie, the helicopter taking the film is clearly seen reflected in one of the skyscrapers.

When Ferris is running down the street near the end of the movie, there is a palm tree in the background. This is because the scene was actually shot in Long Beach, California.

When the exteriors of the Bueller Home are shown as Mr. Rooney tries to break in, there is a Bird of Paradise plant growing in the garden. This is a tropical plant species that would not survive outdoors in Chicago.

There are no high cliffs in Chicago on the shore of Lake Michigan. The scene in question was filmed in Los Angeles.

When the old lady is seen driving behind the wheel, the San Gabriel mountains of southern California can be seen out the back window.

Mr. Rooney's car is ticketed for being next to a "wet pipe" fire hydrant (California style), but Chicago (being a cold weather city) has a dry pipe system.

How is it that the real Abe Froman did not arrive at the Chez Luis (the fancy restaurant) at the same time as Ferris, who was pretending to be him?

Even if Ferris really was Abe Froman, the Chez Quis had a dress code, so the party would not be allowed into the dining room dressed as they were.

Somehow they manage to do all those things and go to all those places in the span of a single school day.

When Katie Bueller checks on Ferris during her lunch break, she opens his door and the mannequin's hand and arm is visibly poking out of the duvet and in her line of sight. It is revealed again when she double checks. She fails to nice that the dummy has dark skin, as opposed to Ferris' fair skin.

The police car that is chasing Jeanie's car at the end of the movie disappears with no explanation.

When Jeanie pulls up to the field in her car and she says "I hate him." You can see the reflection of the boom mic and the camera in her slightly rolled up window.

In the bathroom at Chez Quis, the boom mic is reflected at the top of the mirror.

Ben Stein is billed as an Economics teacher, however a still frame of Ferris's schedule on Rooney's computer (when Rooney is checking Ferris' absences) shows that he doesn't take an economics class.

When Ben Stein is taking attendance, he calls "Adams, Adamly, Adamowski, Adamson ..." However, Adams is after both Adamly and Adamowski in alphabetical order.

While Ferris is singing Danke Schoen, Cameron and Sloane are walking in front of the "Flamingo" sculpture. A blonde extra walks behind them. About two seconds after she leaves the frame on the left, she reappears and watches the filming. When she realizes that she is back on camera, she quickly exits to the left again.

Rooney says that the French phrase "les jeux sont faits" means "the game is up". It really means "the bets are made"; it's what a croupier calls when he spins roulette, to forbid any new bets or changes in bets.

The two parking garage attendants, taking the Ferrari out for over 150 miles, would mean that the "attended" garage was left unattended.