Matt Stifler wants to be just like his big bro, making porn movies and having a good time in college. After sabotaging the school band, he gets sent to band camp where he really doesn't like it at first but then learns how to deal with the bandeez.
Matt Stifler, the younger brother of the legendary Steve Stifler, who made it big as Hollywood porn-producer and shamelessly ignores the idolizing kid brother, may claim the title of Stifmeister as his heritage, but even for his horniest mates he's little more then a bad joke. When Matt alone gets caught red-handed for a prank with the school band's instruments, present high school counselor Sherman 'Sherminator' finds great pleasure in taking revenge on him for the misbehavior Steve excelled even worse in, so instead of expelling the little prick, he condemns him to take part in band camp at Great Oaks, where Jim Levenstein's still understanding dad is filling in for the feared problem counselor. As there are plenty of girls in the competing bands, Matt hopes to turn his (mis)fortune around by smuggling in camera equipment including a robot to shoot saucy, clandestine material for his counterpart to Steve's hit video "Girls Gone Wild", an at least as 'revealing' Bandies Gone Wild. Matt's nerdy, yet also horny roomie Ernie was originally confined to the closet, but is promoted to assistant-producer when he proves himself an invaluable technician. Things get complicated as Matt becomes romantically involved with Elyse, his own school band's director, whose ambition is to beat haughty five-fold winner Brandon Vandecamp -son of a famous, rich father- as band music composer and thus win a good shot at a scholarship for an exclusive music school. For her sake Matt turns musician (on the trivial triangle by her decree, bagpipes in surprising scenes) and proves his leadership skills, but courting a 'decent' girl just doesn't square with voyeurism. —KGF Vissers
This loosely related sequel focuses on Steve Stifler's younger brother Matt Stifler, who is sent to band camp for the summer to avoid expulsion from high school by the counselor, Sherminator. Matt attempts to wire the camp with hidden cameras to turn it into the set for his own "Girls Gone Wild"-type video, but when he falls for his school band's director Elyse, his efforts to stifle his Stiffmeister ways will surely meet with hilarious results. —Anonymous
The original American Pie characters have moved on, except for Sherman and Jim Levenstein's still understanding dad. Steve Stifler's little brother Matt wants to join his brother's business (the original Stifmeister has hit it big producing Girls Gone Wild videos) and after everything Matt has heard from Jim's band-geek wife Michelle, he plans to go back to band camp and make a video of his own: Bandies Gone Wild! —Cinescape
The spin-off movie focuses on Matt Stifler (Tad Hilgenbrinck), the younger brother of Steve Stifler from the previous American Pie films. Matt is eager to enter the family business of making porno films, so he can prove to his older brother that he is "up to the standards of the Stifmeister." Stifler and his friends play a prank on the band students during the seniors' graduation ceremony by spraying pepper spray on the mouthpieces of the band's instruments. Matt narrowly escapes getting caught and stows the can of pepper spray in his front pocket, which subsequently leaks onto his genitals. The band members begin to play "Pomp and Circumstance", only to become too irritated by the pepper spray to continue. During the commotion, one of the students trips and pulls down the back curtain, which reveals Matt, who is washing his pepper-spray-soaked genitals in a drinking fountain, in front of the whole school.
The band leader Elyse Houston (Arielle Kebbel) demands that Stifler be punished for ruining their performance, stating that he always gets away with his pranks because he is the school's star football player. The school's guidance counselor Chuck Sherman ("The Sherminator") (played by Chris Owen from the original American Pie films) decides that a worthwhile punishment would be for Stifler to attend band camp, in the hopes that he would make friends with the "bandies" and not follow in the footsteps of his much-hated brother.
When first arriving, Matt is very disrespectful to the rules and also everyone at Tall Oaks and gets his band group in trouble. He is sent to the office of Noah Levenstein (Jim's father) (Eugene Levy), who works as the camp MACRO (Morale and Conflict Resolution Officer; he's filling in for Michelle as she is now pregnant), recommends that he try to fit in and earn the band's trust, which is the last thing that Matt wants to do. However, a phone call from a friend, who says that earning their trust will get him better footage for his video, inspires Matt to be much more respectful and humble towards the band.
Matt finds out that his dorky roommate Ernie Kapolwitz (Jason Earles) has an extensive knowledge of spy cameras and technology, so Matt agrees to let him help with the filming, making his first friend at Tall Oaks. As Matt "is earning the band's trust" he gets into a big confrontation with their rival band leader, Brandon Van der Camp (Matt Barr), and even goes as far as to accept a duel challenge made by him, having no idea what a "duel" is.
It turns out that a duel is the two performers showing off their music skills, with Brandon playing the snare drum, and Matt playing the triangle. Throughout the majority of the competition it seems that Brandon is the heavy favourite; during Brandon's second round of performing, Matt walks away humiliated. As Brandon is about to be declared the official winner, Matt comes back playing the bagpipes to the tune of 'Play That Funky Music' showing that he is actually a decent player, surprising everyone, including Elyse, who is pleasantly surprised by Matt's performance.
As Matt is still recording the various happenings at the camp, he gradually becomes friends with some of the band members from his school. He gains some respect from Ernie after Matt sets him up on a date with tattooed bandmate Chloe (Crystle Lightning). Matt starts falling for Elyse, who is revealed to have been a friend of Matt's in 8th grade but had a falling out after Matt started hanging around with Steve and his friends and acting like The Stifmeister. Matt is eventually caught with his movies, and his once-friends want nothing more to do with him.
After another talk with Jim's Dad, Matt comes to realize that his brother is not as great or cool as he once thought and that following in his footsteps is not a good idea, so he deletes all the videos he recorded at band camp. He even enlists the help of the band to help Elyse get the band scholarship that Stifler accidentally made her lose in the final days of band camp.
To make it up to Elyse, Matt decides to pull the whole band together to get Elyse the scholarship to the Robards Conservatory. Matt writes up a forged letter on his computer and sends it to Elyse's house. Elyse gets the letter when she is with her friend Chloe. Elyse then gets dropped off at Robards by fellow band member Oscar. When Elyse gets to the front desk she is told by the lady at the desk that the letter she has is a fake.
When Elyse turns around and hears bagpipes, she says to herself "Stifler!" in an exasperated voice. The camera then moves in to Matt who is playing the bagpipes, and after Elyse expresses her anger with him, the rest of the band is revealed and start playing the song that Elyse wrote. When Dr. Choi and her assistant come out to see what the noise is about she mistakenly believes that the entire event has been orchestrated by Elyse and is sufficiently impressed to give her the scholarship.
Elyse then thanks Matt and hugs him, who in turn gives back Elyse her piccolo which he'd thought was a dildo. They then kiss.
Various deleted scenes are shown during the closing credits that did not make the cut.