After Cha Cha brings down her scarf to start the car race on Thunder Road, an Amtrak train is visible above the concrete riverbank at the left of the screen. The F40 locomotive and Amfleet passenger cars began service in the mid 1970s.
"Rama Lama Ding Dong", a song referenced in the lyrics of "We Go Together" , sung throughout both the show and film version, did not surface until the summer of 1961, when it became a million seller for "The Edsels".
In the beginning of "You're the One that I want" Danny Zuko falls down in the dirt and when he gets up his black shirt is dirty in the belly area. Also, Olivia Newton-John's character puts her dusty shoe on his shirt as well. Several scenes later, his shirt is clean again and remains clean for the rest of the song.
A dummy is being burned in effigy during the pep rally; however, the amount of flames on the dummy goes from small to large (the dummy is fully ablaze) then back to small (a closeup shows the fire only on the upper torso and one can still read the undamaged sign on the dummy).
At the start of the 'National Bandstand' dance-off (the "Born to Hand Jive" number), the head of the cowboy decoration in the gym tips forward, spilling wads of paper off the brim of its hat. However, in the establishing shots prior to that there is no paper on the hat brim. In addition, a few seconds later, and as seen in other shots that follow, the head is intact and back in proper position.
In the shake shack, some of the close-ups do not match the other scenes. In far shots, people and trees are behind the bars. Close-ups have no trees or people. The wall colors also change between shots.
At the dance-off, just before Cha-Cha replaces Sandy as Danny's dancing partner, a wide shot shows Danny and Sandy dancing. Cha-Cha walks out from behind some students in a corner. In the close-up, she walks out again.
In the dance contest scene when Vince chats Marty up beside the camera, on her final line she lifts her right hand and her purse visible. When the camera changes angles, her hand has vanished back to her side.
During "Greased Lightning", after switching to the all white shop, the background dancer who hops up onto the shop table at the very back knocks the custom wheel off of its stand. It rolls off and hits a stool. In the next shot, the wheel is back on its stand. In the same scene, the wheel on the stand in front of the second to last table is shown sitting on its stand at the beginning. After a few cuts, a dancer lifts the same wheel back onto its stand from behind the table, then rolls it off instead to put on the car.
All of the actors are far past the typical high school age of 14 to 18 years and do not accurately represent high-school aged children: John Travolta (Danny) was 23 years old at the time of shooting; Stockard Channing (Rizzo) was 33 years old; Olivia Newton-John (Sandy) was 29 years old; Both Barry Pearl (Doody) and Jeff Conaway (Kenickie) were 27 years old; Michael Tucci (Sonny) was 31; Kelly Ward (Putzie), at 21 years old, was the youngest of the bunch, while Didi Conn (Frenchy) was 26 years old at the time of filming.
The goof item below may give away important plot points.
During the dance scene, when the teachers congratulate Eugene and Patty, Eugene starts waving to the students. In the next shot, when the camera is facing the stage, he and all the other students are standing still.