Backstage at the Ramones concert, after Kate finds Tom sprawled out on the floor, while the two of them are talking the shower curtain dress she's wearing comes off her without her making any apparent effort to remove it.
When Dee Dee yells "Hey pizza! Dig in!" the pizza boxes aren't open yet but in the previous shot with Joey in the foreground, the boxes are already open and the rest of the band are already taking out some slices.
When Angel Dust and Riff Randell are continuing to argue about who's in line first, the Ramones pull up. They begin to push and shove each other. Angel's hair starts being pulled up, neatly. As her and Riff push to get the Ramone's attention, Angel's hair falls down. But after the Ramones are done singing, their manager approaches Angel, and her hair is up neatly once again.
When the Ramones are playing "I Want You Around" in Riff's bedroom, Johnny is in a chair playing a wood-grain acoustic guitar. Later in the song, he is still in the same chair, but now playing a red and white electric guitar. At the end of the song, when the scene has moved to the bathroom, he is playing a different white and black electric guitar. (Though, as the scene is technically a dream sequence, strict rules of continuity need not necessarily apply).
At the start of the record burning assembly, the yellow school sign has the motto, "Winning is better than losing". In all subsequent shots, where the sign can be seen in the background behind the students, the longer motto that was seen early in the film is on the sign instead.
The seniors at Vince Lombardi High School wear class buttons which read "1980." The freshman who is the continual victim of upperclassman abuse wears a class button that reads "1984." Freshmen of that year would have been from the class of 1983, not 1984.
Riff is shown putting on the Ramones' "Road to Ruin" album to listen to the song "I Want You Around". This song does not appear on that record.
In the end credits for the Ramones' songs, "Blitzkrieg Bop" is misspelled as "Blitzkreig Bop."
When Riff puts on a Ramones album at the beginning of the film, she starts it from the beginning of one side; but the audience hears "Sheena is a Punk Rocker", which is the fifth song on Side One of _Leave Home_ (US reissue).
During filming of the concert scenes, the camera focused on P.J. Soles and Dey Young ran at the wrong speed, giving the footage a very speeded-up look. The filmmakers added the scenes into the picture anyway.
During the explosions at the school, the "Rock and Roll High School" banner is backwards in one frame, revealing use of a mirror image.
After Mr. McGree (Paul Bartel) gets the "ear-mail", he leaves the classroom. When Fritz follows, Bartel can be seen through the crack in the door waiting behind it.
During the closing credits when the map is burning, it is periodically reconstituted as if it were a recording loop.
During the party at the school, students trap the freshman in a cooking pot and add a box of "Freshman Helper". But the real identity of the product (Hamburger Helper) is evident because the box still reads "Add to 1 lb. hamburger".
When Riff Randall puts the MC5's "High School" on the school's turntable, the record has the Sire Records logo, but "High School" was released by Atlantic Records, on the "Back in the USA" album.
In the concert during the song Pinhead Joey says "D-U-M-B" the subtitles on screen spell "D-M-U-B"
At 9:43 Tom says "Riff Randell, I need to get laid" but his lips aren't moving.
When Eaglebauer is coaching Tom on asking Riff for a date, he mentions that Riff lost her ticket to the Ramones concert. How could he have known within one school day, since he was not present when this happened? Possibly Riff or Kate had told it to Eaglebauer to announce their availability for Tom that night.
When Tom calls Riff from his van, he mentions that he is listening to the "new Ramones album." The song "I Wanna Be Your Boyfriend" can be heard in the background. The problem is "I Wanna Be Your Boyfriend" is from the Ramones' first album "Ramones" (1976). Had Tom actually been listening to their newest album, he would have been listening to "Road to Ruin" (1978)...which does not include the song "I Wanna Be Your Boyfriend".
Riff remarks excitedly to Kate about how the Ramones are all brothers. In fact, none of the Ramones were related to each other.
When Mr. McGree gets the "ear mail" ordering him to meet Miss Togar, he tells the class he has to go to her office. He is actually going to the science lab.